JP2017168385A - Platinum catalyst and manufacturing method thereof, and fuel cell using platinum catalyst - Google Patents
Platinum catalyst and manufacturing method thereof, and fuel cell using platinum catalyst Download PDFInfo
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- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 title claims abstract description 356
- 239000003054 catalyst Substances 0.000 title claims abstract description 270
- 229910052697 platinum Inorganic materials 0.000 title claims abstract description 130
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 34
- 239000000446 fuel Substances 0.000 title claims abstract description 12
- 239000002245 particle Substances 0.000 claims abstract description 97
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims abstract description 49
- 229910052799 carbon Inorganic materials 0.000 claims abstract description 46
- 150000001875 compounds Chemical class 0.000 claims abstract description 34
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims abstract description 25
- 229910052751 metal Inorganic materials 0.000 claims abstract description 24
- 239000002184 metal Substances 0.000 claims abstract description 24
- DCQBZYNUSLHVJC-UHFFFAOYSA-N 3-triethoxysilylpropane-1-thiol Chemical group CCO[Si](OCC)(OCC)CCCS DCQBZYNUSLHVJC-UHFFFAOYSA-N 0.000 claims abstract description 23
- 239000011248 coating agent Substances 0.000 claims abstract description 23
- 238000000576 coating method Methods 0.000 claims abstract description 23
- 238000000034 method Methods 0.000 claims abstract description 21
- 125000003396 thiol group Chemical group [H]S* 0.000 claims abstract description 15
- 239000000377 silicon dioxide Substances 0.000 claims abstract description 12
- 229910052717 sulfur Inorganic materials 0.000 claims abstract description 10
- 125000004434 sulfur atom Chemical group 0.000 claims abstract description 10
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 claims abstract description 8
- 125000004430 oxygen atom Chemical group O* 0.000 claims abstract description 8
- TWNQGVIAIRXVLR-UHFFFAOYSA-N oxo(oxoalumanyloxy)alumane Chemical compound O=[Al]O[Al]=O TWNQGVIAIRXVLR-UHFFFAOYSA-N 0.000 claims abstract description 3
- 235000012239 silicon dioxide Nutrition 0.000 claims abstract description 3
- 239000004408 titanium dioxide Substances 0.000 claims abstract description 3
- KDLHZDBZIXYQEI-UHFFFAOYSA-N Palladium Chemical compound [Pd] KDLHZDBZIXYQEI-UHFFFAOYSA-N 0.000 claims description 138
- 239000011258 core-shell material Substances 0.000 claims description 24
- 230000007062 hydrolysis Effects 0.000 claims description 23
- 238000006460 hydrolysis reaction Methods 0.000 claims description 23
- 239000007771 core particle Substances 0.000 claims description 22
- BOTDANWDWHJENH-UHFFFAOYSA-N Tetraethyl orthosilicate Chemical compound CCO[Si](OCC)(OCC)OCC BOTDANWDWHJENH-UHFFFAOYSA-N 0.000 claims description 19
- 239000010949 copper Substances 0.000 claims description 19
- 239000012298 atmosphere Substances 0.000 claims description 18
- 239000006185 dispersion Substances 0.000 claims description 18
- 229910052763 palladium Inorganic materials 0.000 claims description 17
- 238000006722 reduction reaction Methods 0.000 claims description 16
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 claims description 15
- 239000000243 solution Substances 0.000 claims description 14
- 229910001260 Pt alloy Inorganic materials 0.000 claims description 13
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 13
- 239000001301 oxygen Substances 0.000 claims description 13
- 229910052760 oxygen Inorganic materials 0.000 claims description 13
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 12
- 239000007864 aqueous solution Substances 0.000 claims description 12
- 239000003795 chemical substances by application Substances 0.000 claims description 11
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims description 10
- 229910052802 copper Inorganic materials 0.000 claims description 10
- 239000011261 inert gas Substances 0.000 claims description 8
- 230000008569 process Effects 0.000 claims description 8
- 229910017052 cobalt Inorganic materials 0.000 claims description 7
- 239000010941 cobalt Substances 0.000 claims description 7
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 claims description 7
- 229910052759 nickel Inorganic materials 0.000 claims description 7
- 229910052742 iron Inorganic materials 0.000 claims description 6
- 230000001590 oxidative effect Effects 0.000 claims description 6
- 125000005369 trialkoxysilyl group Chemical group 0.000 claims description 5
- 238000001914 filtration Methods 0.000 claims description 4
- 239000003513 alkali Substances 0.000 claims description 2
- 238000001035 drying Methods 0.000 claims description 2
- 125000002887 hydroxy group Chemical group [H]O* 0.000 abstract description 9
- 230000007423 decrease Effects 0.000 abstract description 8
- 238000012360 testing method Methods 0.000 abstract description 5
- 239000000969 carrier Substances 0.000 abstract 1
- 229910004298 SiO 2 Inorganic materials 0.000 description 48
- 230000000694 effects Effects 0.000 description 22
- WYTZZXDRDKSJID-UHFFFAOYSA-N (3-aminopropyl)triethoxysilane Chemical compound CCO[Si](OCC)(OCC)CCCN WYTZZXDRDKSJID-UHFFFAOYSA-N 0.000 description 11
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 10
- 230000000052 comparative effect Effects 0.000 description 10
- 229910052739 hydrogen Inorganic materials 0.000 description 10
- 238000003917 TEM image Methods 0.000 description 9
- ZMANZCXQSJIPKH-UHFFFAOYSA-N Triethylamine Chemical compound CCN(CC)CC ZMANZCXQSJIPKH-UHFFFAOYSA-N 0.000 description 9
- 238000010438 heat treatment Methods 0.000 description 9
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 8
- 125000004429 atom Chemical group 0.000 description 8
- 239000007789 gas Substances 0.000 description 8
- 239000001257 hydrogen Substances 0.000 description 8
- 239000000126 substance Substances 0.000 description 8
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 8
- 238000002441 X-ray diffraction Methods 0.000 description 7
- 238000010586 diagram Methods 0.000 description 7
- 238000002149 energy-dispersive X-ray emission spectroscopy Methods 0.000 description 7
- 230000009467 reduction Effects 0.000 description 7
- -1 trihydroxysilyl group Chemical group 0.000 description 7
- 238000004458 analytical method Methods 0.000 description 6
- 239000007787 solid Substances 0.000 description 6
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 5
- 239000003929 acidic solution Substances 0.000 description 5
- 230000002776 aggregation Effects 0.000 description 5
- 229910052786 argon Inorganic materials 0.000 description 5
- 238000003756 stirring Methods 0.000 description 5
- 229910018072 Al 2 O 3 Inorganic materials 0.000 description 4
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 4
- 239000011865 Pt-based catalyst Substances 0.000 description 4
- 229910010413 TiO 2 Inorganic materials 0.000 description 4
- 238000004220 aggregation Methods 0.000 description 4
- 230000003197 catalytic effect Effects 0.000 description 4
- 238000011068 loading method Methods 0.000 description 4
- 239000011259 mixed solution Substances 0.000 description 4
- 239000000203 mixture Substances 0.000 description 4
- 239000002105 nanoparticle Substances 0.000 description 4
- 229910052710 silicon Inorganic materials 0.000 description 4
- 238000002411 thermogravimetry Methods 0.000 description 4
- 229910045601 alloy Inorganic materials 0.000 description 3
- 239000000956 alloy Substances 0.000 description 3
- 230000015572 biosynthetic process Effects 0.000 description 3
- 230000005587 bubbling Effects 0.000 description 3
- 239000013626 chemical specie Substances 0.000 description 3
- 230000007797 corrosion Effects 0.000 description 3
- 238000005260 corrosion Methods 0.000 description 3
- 238000002484 cyclic voltammetry Methods 0.000 description 3
- 230000018044 dehydration Effects 0.000 description 3
- 238000006297 dehydration reaction Methods 0.000 description 3
- 229910001873 dinitrogen Inorganic materials 0.000 description 3
- 238000007254 oxidation reaction Methods 0.000 description 3
- MUMZUERVLWJKNR-UHFFFAOYSA-N oxoplatinum Chemical compound [Pt]=O MUMZUERVLWJKNR-UHFFFAOYSA-N 0.000 description 3
- 229910003446 platinum oxide Inorganic materials 0.000 description 3
- 238000002360 preparation method Methods 0.000 description 3
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 2
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 2
- 125000003545 alkoxy group Chemical group 0.000 description 2
- 229910052782 aluminium Chemical group 0.000 description 2
- 239000003575 carbonaceous material Substances 0.000 description 2
- 238000009833 condensation Methods 0.000 description 2
- 230000005494 condensation Effects 0.000 description 2
- 238000007796 conventional method Methods 0.000 description 2
- 239000013078 crystal Substances 0.000 description 2
- 238000010828 elution Methods 0.000 description 2
- 239000010419 fine particle Substances 0.000 description 2
- QWPPOHNGKGFGJK-UHFFFAOYSA-N hypochlorous acid Chemical compound ClO QWPPOHNGKGFGJK-UHFFFAOYSA-N 0.000 description 2
- 230000006872 improvement Effects 0.000 description 2
- 150000002500 ions Chemical class 0.000 description 2
- 150000002739 metals Chemical class 0.000 description 2
- 238000010899 nucleation Methods 0.000 description 2
- 230000003647 oxidation Effects 0.000 description 2
- PIBWKRNGBLPSSY-UHFFFAOYSA-L palladium(II) chloride Chemical compound Cl[Pd]Cl PIBWKRNGBLPSSY-UHFFFAOYSA-L 0.000 description 2
- VLTRZXGMWDSKGL-UHFFFAOYSA-N perchloric acid Chemical compound OCl(=O)(=O)=O VLTRZXGMWDSKGL-UHFFFAOYSA-N 0.000 description 2
- 230000002093 peripheral effect Effects 0.000 description 2
- 239000005518 polymer electrolyte Substances 0.000 description 2
- 230000002441 reversible effect Effects 0.000 description 2
- 229920006395 saturated elastomer Polymers 0.000 description 2
- 239000011734 sodium Substances 0.000 description 2
- 239000010936 titanium Chemical group 0.000 description 2
- 229910052719 titanium Inorganic materials 0.000 description 2
- GETQZCLCWQTVFV-UHFFFAOYSA-N trimethylamine Chemical compound CN(C)C GETQZCLCWQTVFV-UHFFFAOYSA-N 0.000 description 2
- 238000004846 x-ray emission Methods 0.000 description 2
- AHYFYQKMYMKPKD-UHFFFAOYSA-N 3-ethoxysilylpropan-1-amine Chemical compound CCO[SiH2]CCCN AHYFYQKMYMKPKD-UHFFFAOYSA-N 0.000 description 1
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 description 1
- 101150003085 Pdcl gene Proteins 0.000 description 1
- 229910018879 Pt—Pd Inorganic materials 0.000 description 1
- 229910008051 Si-OH Inorganic materials 0.000 description 1
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 description 1
- 229910006358 Si—OH Inorganic materials 0.000 description 1
- 239000006230 acetylene black Substances 0.000 description 1
- 230000002378 acidificating effect Effects 0.000 description 1
- 238000005054 agglomeration Methods 0.000 description 1
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 1
- 238000000137 annealing Methods 0.000 description 1
- 229910052785 arsenic Inorganic materials 0.000 description 1
- 230000008901 benefit Effects 0.000 description 1
- 239000006229 carbon black Substances 0.000 description 1
- 239000002041 carbon nanotube Substances 0.000 description 1
- 229910021393 carbon nanotube Inorganic materials 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 239000007809 chemical reaction catalyst Substances 0.000 description 1
- 239000003638 chemical reducing agent Substances 0.000 description 1
- 238000006482 condensation reaction Methods 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 238000003795 desorption Methods 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 230000009881 electrostatic interaction Effects 0.000 description 1
- 230000001747 exhibiting effect Effects 0.000 description 1
- 238000011835 investigation Methods 0.000 description 1
- 239000003273 ketjen black Substances 0.000 description 1
- 239000012528 membrane Substances 0.000 description 1
- 229910001510 metal chloride Inorganic materials 0.000 description 1
- 229910017604 nitric acid Inorganic materials 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 239000012299 nitrogen atmosphere Substances 0.000 description 1
- 229910000510 noble metal Inorganic materials 0.000 description 1
- 239000003960 organic solvent Substances 0.000 description 1
- 125000002524 organometallic group Chemical group 0.000 description 1
- YJVFFLUZDVXJQI-UHFFFAOYSA-L palladium(ii) acetate Chemical compound [Pd+2].CC([O-])=O.CC([O-])=O YJVFFLUZDVXJQI-UHFFFAOYSA-L 0.000 description 1
- GPNDARIEYHPYAY-UHFFFAOYSA-N palladium(ii) nitrate Chemical compound [Pd+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O GPNDARIEYHPYAY-UHFFFAOYSA-N 0.000 description 1
- 238000007747 plating Methods 0.000 description 1
- 231100000572 poisoning Toxicity 0.000 description 1
- 230000000607 poisoning effect Effects 0.000 description 1
- 238000012805 post-processing Methods 0.000 description 1
- 238000010248 power generation Methods 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 230000008707 rearrangement Effects 0.000 description 1
- 125000005372 silanol group Chemical group 0.000 description 1
- 229910052709 silver Inorganic materials 0.000 description 1
- 239000004332 silver Substances 0.000 description 1
- 229910052708 sodium Inorganic materials 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 238000001308 synthesis method Methods 0.000 description 1
- 230000002194 synthesizing effect Effects 0.000 description 1
- QQQSFSZALRVCSZ-UHFFFAOYSA-N triethoxysilane Chemical compound CCO[SiH](OCC)OCC QQQSFSZALRVCSZ-UHFFFAOYSA-N 0.000 description 1
Classifications
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/30—Hydrogen technology
- Y02E60/50—Fuel cells
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
- Y02P70/50—Manufacturing or production processes characterised by the final manufactured product
Landscapes
- Catalysts (AREA)
- Inert Electrodes (AREA)
- Fuel Cell (AREA)
Abstract
Description
本発明は、燃料電池において酸素還元反応の触媒として用いるのに適した白金触媒、その製造方法、及び当該触媒を用いた燃料電池に関する。 The present invention relates to a platinum catalyst suitable for use as a catalyst for an oxygen reduction reaction in a fuel cell, a method for producing the same, and a fuel cell using the catalyst.
固体高分子形燃料電池(PEFC)は、アノード側で水素の酸化反応を、カソード側で酸素の還元反応を起こすことにより、水のみを生成するクリーンエネルギーデバイスであって、カソード側の触媒として、白金(Pt)を使用するものが知られている。貴金属である白金を用いる触媒は、触媒活性や電気伝導性が高く、また、周辺環境の状態や周辺環境に存在する物質による腐食や被毒を受けにくいという利点を有する。 A polymer electrolyte fuel cell (PEFC) is a clean energy device that produces only water by causing an oxidation reaction of hydrogen on the anode side and a reduction reaction of oxygen on the cathode side. As a catalyst on the cathode side, Those using platinum (Pt) are known. A catalyst using platinum, which is a noble metal, has high catalytic activity and high electrical conductivity, and has an advantage that it is less susceptible to corrosion and poisoning due to the state of the surrounding environment and substances present in the surrounding environment.
一方で、白金は資源量が少なく価格が高いという問題があり、その利用効率や耐久性を向上させて使用量を低減するために種々の検討が進められている。検討の一つとして、異種金属上に白金を被覆してなる白金コアシェル触媒が注目されている。白金コアシェル触媒は、触媒活性を発揮する白金原子は触媒粒子の最外層に露出した白金原子のみであることに着目して考案されたもので、白金原子層(シェル)で被覆された異種金属微粒子(コア)が、カーボン等の担体に高分散担持された構成を有する。 On the other hand, platinum has a problem that the amount of resources is small and the price is high, and various studies are being conducted to improve the utilization efficiency and durability and reduce the amount of use. As one of the studies, a platinum core-shell catalyst obtained by coating platinum on a different metal has attracted attention. The platinum core-shell catalyst was devised by focusing on the fact that the platinum atoms exhibiting catalytic activity are only the platinum atoms exposed in the outermost layer of the catalyst particles. The dissimilar metal fine particles covered with the platinum atomic layer (shell) The (core) is configured to be highly dispersed and supported on a carrier such as carbon.
白金コアシェル触媒のコア金属の一つとして、パラジウム(Pd)が知られている。非特許文献1及び非特許文献2には、コア金属としてPdを使用した場合、PEFCでの酸素還元反応(Oxygen Reduction Reaction: ORR)活性が高まることが開示されている。Pdの格子定数(0.38898 nm)はPt(0.39231 nm)よりも小さいため、Pdコア上に設けたPtシェルには僅かな圧縮応力が発生する。この圧縮応力によって、Ptシェル表面で酸素還元反応が進行しやすい状況が実現され、ORR活性が高まったものと考えられている。 Palladium (Pd) is known as one of the core metals of the platinum core-shell catalyst. Non-Patent Document 1 and Non-Patent Document 2 disclose that when Pd is used as a core metal, oxygen reduction reaction (ORR) activity in PEFC is enhanced. Since the lattice constant (0.38898 nm) of Pd is smaller than Pt (0.39231 nm), a slight compressive stress is generated in the Pt shell provided on the Pd core. It is thought that this compressive stress realizes a situation where the oxygen reduction reaction easily proceeds on the surface of the Pt shell and increases the ORR activity.
白金をシェル、パラジウムをコアとしたコアシェル触媒では、上述のようにORR活性が向上する一方で、Pdの標準酸化還元電位(0.92 V vs. NHE)がPt(1.19 V vs. NHE)に比べて低いため、その耐久性に問題がある。非特許文献3では、カーボン担持Pdコア/Ptシェル触媒(以後、Pt/Pd/C触媒と記述することもある。)をカソードに使用したPEFCにおいて、発電によりPdコアの一部が酸化溶解し、固体高分子電解質膜中に金属Pdが再析出し、Pdバンドが現れることが報告されている。 In the core-shell catalyst with platinum as the shell and palladium as the core, the ORR activity is improved as described above, while the standard redox potential of Pd (0.92 V vs. NHE) is higher than that of Pt (1.19 V vs. NHE). Since it is low, there is a problem in its durability. In Non-Patent Document 3, in a PEFC using a carbon-supported Pd core / Pt shell catalyst (hereinafter also referred to as a Pt / Pd / C catalyst) as a cathode, a part of the Pd core is oxidized and dissolved by power generation. It has been reported that metal Pd is reprecipitated in the solid polymer electrolyte membrane and a Pd band appears.
発明者らは既に、Pdコアの酸化溶出は触媒の耐久性の観点からは問題である一方で、Pdの酸化溶出によってPt/Pd/C触媒の粒径と形態に変化が生じ、ORR活性が高まることを見出している。特許文献1には、従来、触媒の電位サイクル耐久性試験(Accelerated Durability Test, ADT)として行われてきた電圧の印加が、Pt/Pd/C触媒の活性を向上させる結果をもたらすことが開示されている。また特許文献1には、Pt/Pd/C触媒に、Ptの酸化物還元開始電位よりも高い電位と、Ptの酸化物生成開始電位よりも低い電位とを繰り返し与えることによって、Pt/Pd/C触媒の活性が向上することも開示されている。 The inventors have already described that the oxidation elution of Pd core is a problem from the viewpoint of the durability of the catalyst, but the oxidation elution of Pd causes a change in the particle size and form of the Pt / Pd / C catalyst, resulting in an ORR activity. It has been found to increase. Patent Document 1 discloses that application of a voltage, which has been conventionally performed as an accelerated cycle durability test (ADT) of a catalyst, results in improving the activity of a Pt / Pd / C catalyst. ing. Further, Patent Document 1 discloses that a Pt / Pd / C catalyst is repeatedly given a potential higher than the Pt oxide reduction start potential and a potential lower than the Pt oxide formation start potential, whereby Pt / Pd / C. It is also disclosed that the activity of the C catalyst is improved.
特許文献1に開示された具体的な電位付与方法は、プロトンを含む酸性溶液中に白金コアシェル触媒を分散し、酸化還元電位が当該白金コアシェル触媒の酸化物生成開始電位よりも低い金属を共存させながら、酸素供給下に撹拌するという方法であった。当該方法は全く新規な手法であり、一定の効果を得るものであったが、ORR活性のさらなる向上が期待されていた。 In the specific potential application method disclosed in Patent Document 1, a platinum core-shell catalyst is dispersed in an acidic solution containing protons, and a metal having a redox potential lower than the oxide generation start potential of the platinum core-shell catalyst is allowed to coexist. However, it was a method of stirring under oxygen supply. This method is a completely new method and has obtained a certain effect, but further improvement of ORR activity has been expected.
一方、特許文献2には白金合金の触媒とその製造方法が開示されている。特許文献2に開示された製造方法は、白金の有機金属錯体と金属塩化物を有機溶媒に分散してから、還元剤を加えて調製した混合溶液を加圧及び加熱して、2nm以下の径の白金合金ナノ粒子を合成する工程と、前記白金合金ナノ粒子を真空中300℃以上1000℃以下の温度で加熱(アニール)して、その直径を2nm以上100nm以下とする工程とを有する。特許文献2の発明では、白金合金ナノ粒子を合成した後に加熱(アニール)を行うことによって、合金粒子の粒子径を2nm以上100nm以下に調整し、特定の結晶形の白金合金粒子を得ることができると考えられている。
しかしながら、このような特定の結晶形の白金合金粒子の場合であっても、ADTを行うと、電気化学的表面積(ECSA)が大きく減少する結果、ORR活性が低下し、耐久性が不十分であるという問題点があった。
On the other hand, Patent Document 2 discloses a platinum alloy catalyst and a method for producing the same. In the production method disclosed in Patent Document 2, a mixed solution prepared by adding a reducing agent after dispersing an organometallic complex of platinum and a metal chloride in an organic solvent is pressurized and heated to have a diameter of 2 nm or less. The platinum alloy nanoparticles are synthesized, and the platinum alloy nanoparticles are heated (annealed) in a vacuum at a temperature of 300 ° C. or higher and 1000 ° C. or lower to have a diameter of 2 nm or more and 100 nm or less. In the invention of Patent Document 2, by synthesizing platinum alloy nanoparticles and then heating (annealing), the particle diameter of the alloy particles is adjusted to 2 nm or more and 100 nm or less to obtain platinum alloy particles having a specific crystal form. It is considered possible.
However, even in the case of such a specific crystal form of platinum alloy particles, when ADT is performed, the electrochemical surface area (ECSA) is greatly reduced, resulting in decreased ORR activity and insufficient durability. There was a problem that there was.
更に、下記の特許文献3には、白金担持カーボン触媒を分散させた溶液に3−アミノプロピルエトキシシラン(APTES)を添加して撹拌した後、テトラエトキシシラン(TEOS)を添加して撹拌し、その後、水素還元することによって製造された、カーボンに担持された白金がシリカ(SiO2成分)で被覆されてなる触媒が開示されているが、この触媒の場合、白金の表面だけでなくカーボンの表面にも、厚い均一なシリカ被膜が被覆されているために、電池に組み込んだ際、カーボンを被覆しているシリカによって電気抵抗が大きくなり、電池特性が低下するという問題点があった。 Furthermore, in the following Patent Document 3, 3-aminopropylethoxysilane (APTES) is added to a solution in which a platinum-supported carbon catalyst is dispersed and stirred, and then tetraethoxysilane (TEOS) is added and stirred. Thereafter, there is disclosed a catalyst produced by hydrogen reduction, in which platinum supported on carbon is coated with silica (SiO 2 component). In this catalyst, not only the surface of platinum but also carbon Since the surface is also coated with a thick uniform silica film, there is a problem that when the battery is incorporated in the battery, the electric resistance is increased by the silica covering the carbon, and the battery characteristics are deteriorated.
本発明は、白金と白金以外の金属とを組み合わせて用いた白金触媒において、ADTによる触媒粒子の凝集が起こり難く、耐久性に優れたカーボン担持白金触媒、及び、かかる触媒を得るための製造方法を提供することを目的とする。 The present invention relates to a platinum catalyst using a combination of platinum and a metal other than platinum, in which the catalyst particles do not easily aggregate due to ADT, have excellent durability, and a production method for obtaining such a catalyst. The purpose is to provide.
発明者らは、Pt質量当たりの活性を示すORR質量活性(ORR mass activity:MA)は、ORR面積比活性(ORR specific activity:SA)と電気化学的表面積(Electro-Chemical Surface Area:ECSA)との積で表されることに着目し、SA及びECSAの両方を高めることによって、ORR質量活性を一層向上させることが可能であると考えた。そして、電位サイクル耐久性試験(ADT)を経た白金コアシェル触媒の粒子の一部に凝集が生じていることから、当該凝集を抑制することによってECSAの低下を抑止し、もってORR質量活性の向上を図ることに着想し、カーボンに担持された触媒粒子(白金と白金以外の金属とを含む)を、一端側にチオール基を有し、他端側にトリアルコキシシリル基を有する化合物(種付け剤)と反応させると、チオール基の硫黄原子の孤立電子対が触媒粒子に配位結合し、選択的に触媒粒子が被覆され、他端側のトリアルコキシシリル基を加水分解してトリヒドロキシシリル基とした後、テトラアルコキシシラン化合物、テトラアルコキシチタン化合物又はトリアルコキシアルミニウム化合物と反応させて加水分解し、その後、非酸化性雰囲気で加熱を行うと、触媒粒子が担持されていないカーボン担体の表面部分が露出したままで、カーボン担体に担持された触媒粒子の表面だけが、シリカ(SiO2)被膜、チタニア(TiO2)被膜、アルミナ(Al2O3)被膜によって被覆されることを見出し、かかる構造のカーボン担持白金触媒が、ADTによる触媒粒子の凝集が起こり難く、優れた耐久性を有しており、酸素還元反応の触媒として有用であることを確認し、本発明に至った。 The inventors have determined that ORR mass activity (MA) indicating activity per Pt mass is ORR specific activity (SA) and electrochemical surface area (ECSA). Focusing on the fact that it is expressed by the product of the above, we thought that it is possible to further improve the ORR mass activity by increasing both SA and ECSA. And since aggregation has occurred in some of the particles of the platinum core-shell catalyst that has undergone the potential cycle durability test (ADT), by suppressing the aggregation, the decrease in ECSA is suppressed, thereby improving the ORR mass activity. Inspired by the plan, a catalyst particle (including platinum and a metal other than platinum) supported on carbon, a compound having a thiol group on one end and a trialkoxysilyl group on the other end (seeding agent) , The lone pair of sulfur atom of the thiol group is coordinated to the catalyst particle, and the catalyst particle is selectively coated, and the trialkoxysilyl group on the other end side is hydrolyzed to form a trihydroxysilyl group. Then, it is hydrolyzed by reacting with a tetraalkoxysilane compound, tetraalkoxytitanium compound or trialkoxyaluminum compound, and then heated in a non-oxidizing atmosphere, While the surface portion of the carbon support medium particles is not carried is exposed, only the supported surface of the catalyst particles to the carbon carrier is silica (SiO 2) film, titania (TiO 2) film, an alumina (Al 2 O 3 ) The carbon-supported platinum catalyst having such a structure is found to be covered with a coating, and the catalyst particles are hardly aggregated by ADT, have excellent durability, and are useful as a catalyst for oxygen reduction reaction. The present invention was confirmed.
本明細書では、触媒活性を有する物質として白金を利用する触媒をまとめて、白金触媒と称しており、白金触媒には、白金コアシェル触媒と白金合金触媒の両方が含まれる。 In the present specification, catalysts that use platinum as a substance having catalytic activity are collectively referred to as a platinum catalyst, and the platinum catalyst includes both a platinum core-shell catalyst and a platinum alloy catalyst.
すなわち本発明は、
[1]白金と白金以外の金属とを含む触媒粒子がカーボン担体の表面に担持されてなる燃料電池用の白金触媒であって、前記触媒粒子の表面には、一端側にチオール基の硫黄原子を有し、他端側に水酸基の酸素原子を有する連結構造部が、当該連結構造部における前記チオール基の硫黄原子の孤立電子対が前記触媒粒子に配位して結合しており、前記水酸基の酸素原子側には、当該酸素原子と結合した、二酸化ケイ素、二酸化チタン又は酸化アルミニウムの被膜が存在し、当該被膜によって前記触媒粒子の表面が被覆されており、前記触媒粒子が担持されていない前記カーボン担体の表面部分は前記被膜により被覆されずにカーボン担体が露出していることを特徴とする白金触媒に関する。
That is, the present invention
[1] A platinum catalyst for a fuel cell, in which catalyst particles containing platinum and a metal other than platinum are supported on the surface of a carbon support, and a sulfur atom of a thiol group on one end side of the surface of the catalyst particles Having a hydroxyl group oxygen atom on the other end, the lone pair of sulfur atoms of the thiol group in the linkage structure is coordinated to the catalyst particle and bonded thereto, On the oxygen atom side, a coating of silicon dioxide, titanium dioxide, or aluminum oxide bonded to the oxygen atom exists, and the surface of the catalyst particles is covered with the coating, and the catalyst particles are not supported. The surface of the carbon support is not covered with the coating film, and the carbon support is exposed.
また本発明は、
[2]前記連結構造部を形成している化合物が、3−メルカプトプロピルトリエトキシシラン(MPTS)であることを特徴とする、[1]に記載の白金触媒に関する。
The present invention also provides
[2] The platinum catalyst according to [1], wherein the compound forming the connecting structure part is 3-mercaptopropyltriethoxysilane (MPTS).
また本発明は、
[3]前記触媒粒子が、パラジウムを含有するコア粒子と、当該コア粒子の表面に形成された白金シェルとを有する白金コアシェル触媒であることを特徴とする、[1]又は[2]に記載の白金触媒に関する。
The present invention also provides
[3] The catalyst particle according to [1] or [2], wherein the catalyst particle is a platinum core-shell catalyst having a core particle containing palladium and a platinum shell formed on a surface of the core particle. The platinum catalyst.
また本発明は、
[4]前記触媒粒子が、白金と、パラジウム、コバルト、ニッケル、鉄又は銅との白金合金触媒であることを特徴とする、[1]又は[2]に記載の白金触媒に関する。
The present invention also provides
[4] The platinum catalyst according to [1] or [2], wherein the catalyst particle is a platinum alloy catalyst of platinum and palladium, cobalt, nickel, iron, or copper.
さらに本発明は、
[5]白金と白金以外の金属とを含む触媒粒子がカーボン担体の表面に担持されてなる燃料電池用の白金触媒の製造方法であって、
白金と白金以外の金属とを含む触媒粒子がカーボン担体に担持された触媒を準備し、当該触媒を水溶液中にて分散させる工程と
不活性気体存在下にて、上記工程で得られた分散溶液にアルカリ剤を添加して当該分散溶液をアルカリ性に(当該分散溶液のpHが10.5以上と)なるようにし、その後、一端側にチオール基を有し、他端側にトリアルコキシシリル基を有する連結化合物を添加して第1の加水分解を行う工程と、
上記加水分解後の分散溶液に、テトラアルコキシシラン化合物、テトラアルコキシチタン化合物又はトリアルコキシアルミニウム化合物を添加して第2の加水分解を行う工程と、
上記加水分解後の触媒を濾別して乾燥させ、非酸化性雰囲気で熱処理する工程
を含むことを特徴とする白金触媒の製造方法に関する。
Furthermore, the present invention provides
[5] A method for producing a platinum catalyst for a fuel cell in which catalyst particles containing platinum and a metal other than platinum are supported on the surface of a carbon support,
Preparing a catalyst in which catalyst particles containing platinum and a metal other than platinum are supported on a carbon carrier, and dispersing the catalyst in an aqueous solution; in the presence of an inert gas, the dispersion solution obtained in the above step An alkaline agent is added to the dispersion solution so that the dispersion solution becomes alkaline (pH of the dispersion solution is 10.5 or more). Thereafter, a thiol group is provided on one end side, and a trialkoxysilyl group is provided on the other end side. Adding a connecting compound having a first hydrolysis,
A step of performing a second hydrolysis by adding a tetraalkoxysilane compound, a tetraalkoxytitanium compound or a trialkoxyaluminum compound to the dispersion solution after the hydrolysis;
The present invention relates to a method for producing a platinum catalyst, comprising the steps of filtering and drying the hydrolyzed catalyst, and performing a heat treatment in a non-oxidizing atmosphere.
また本発明は、
[6]前記連結化合物が、3−メルカプトプロピルトリエトキシシラン(MPTES)であることを特徴とする、[5]に記載の白金触媒の製造方法に関する。
The present invention also provides
[6] The method for producing a platinum catalyst according to [5], wherein the linking compound is 3-mercaptopropyltriethoxysilane (MPTES).
また本発明は、
[7]前記第2の加水分解を行う工程にて添加される化合物が、テトラエトキシシラン(TEOS)であることを特徴とする、[5]又は[6]に記載の白金触媒の製造方法に関する。
The present invention also provides
[7] The method for producing a platinum catalyst according to [5] or [6], wherein the compound added in the second hydrolysis step is tetraethoxysilane (TEOS). .
また本発明は、
[8]前記触媒粒子が、パラジウムを含有するコア粒子と、当該コア粒子の表面に形成された白金シェルとを有する白金コアシェル触媒であることを特徴とする、[5]〜[7]のいずれか1項に記載の白金触媒の製造方法に関する。
The present invention also provides
[8] Any one of [5] to [7], wherein the catalyst particle is a platinum core-shell catalyst having palladium-containing core particles and a platinum shell formed on the surface of the core particles. This invention relates to a method for producing a platinum catalyst according to claim 1.
また本発明は、
[9]前記触媒粒子が、白金と、パラジウム、コバルト、ニッケル、鉄又は銅との白金合金触媒であることを特徴とする、[5]〜[7]のいずれか1項に記載の白金触媒の製造方法に関する。
The present invention also provides
[9] The platinum catalyst according to any one of [5] to [7], wherein the catalyst particle is a platinum alloy catalyst of platinum and palladium, cobalt, nickel, iron, or copper. It relates to the manufacturing method.
さらに本発明は、
[10][1]〜[4]のいずれか1項に記載の白金触媒を酸素還元反応の触媒として利用する燃料電池に関する。
Furthermore, the present invention provides
[10] The present invention relates to a fuel cell using the platinum catalyst according to any one of [1] to [4] as an oxygen reduction reaction catalyst.
本発明によれば、カーボン担体に担持された触媒粒子の表面だけがシリカ被膜等によって被覆されており、触媒粒子が担持されていないカーボン担体の表面部分には当該被膜が存在せずにカーボン担体が露出したままの構造を有した白金触媒が得られ、この白金触媒は、カーボン担体の表面には絶縁性の被膜が存在していないために電池特性が低下することなく、触媒粒子の表面を覆った被膜によって電位サイクル耐久性試験(ADT)による触媒粒子の凝集が起こり難く、電気化学的表面積(ECSA)の低下が抑制され、優れた耐久性を示すので、酸素還元反応の触媒として非常に有用である。 According to the present invention, only the surface of the catalyst particles supported on the carbon support is coated with a silica coating or the like, and the carbon support is not present on the surface portion of the carbon support on which the catalyst particles are not supported. Thus, a platinum catalyst having a structure in which the catalyst is exposed is obtained, and the platinum catalyst does not have an insulating coating on the surface of the carbon support, so that the surface of the catalyst particles is not degraded without deterioration of battery characteristics. The coated film is less likely to agglomerate catalyst particles in the potential cycle durability test (ADT), suppresses the decrease in electrochemical surface area (ECSA), and exhibits excellent durability. Useful.
本発明の白金触媒は、図7の下側の模式図に示されるように、白金と白金以外の金属とを含む触媒粒子が、当該触媒粒子の表面が酸化物被膜(SiO2、TiO2又はAl2O3被膜)によって被覆された状態でカーボン担体の表面に担持されており、触媒粒子が担持されていないカーボン担体の表面部分は、上記酸化物被膜により被覆されずにカーボン担体が露出した構造を有している。そして、この触媒粒子と酸化物被膜との間には、特定の化学構造を有した連結構造部(一端側にチオール基の硫黄原子を有し、他端側に水酸基の酸素原子を有する化学構造部)が存在しており、当該連結構造部におけるチオール基の硫黄原子の孤立電子対が、上記触媒粒子の表面に配位結合し、水酸基の酸素原子が、上記酸化物被膜を構成しているSi原子、Ti原子又はAl原子と結合している。
本発明では、触媒粒子の表面に選択的に結合し得る上記連結構造部として、3−メルカプトプロピルトリエトキシシラン(MPTES)由来の連結構造部が好ましいが、これに限定されるものではなく、分子の両末端にチオール基(-SH)と水酸基(-OH)を有する物質であれば使用することができる。上記の酸化物被膜としてはSiO2被膜が好ましいが、これに限定されるものではなく、TiO2あるいはAl2O3であってもよく、また、SiO2とこれらの混合酸化物であってもよい。
As shown in the schematic diagram on the lower side of FIG. 7, the platinum catalyst of the present invention has a catalyst particle containing platinum and a metal other than platinum, and the surface of the catalyst particle is an oxide film (SiO 2 , TiO 2 or Al 2 O 3 coating) is supported on the surface of the carbon support, and the surface of the carbon support on which the catalyst particles are not supported is not covered with the oxide coating and the carbon support is exposed. It has a structure. And between this catalyst particle and the oxide film, there is a connecting structure part having a specific chemical structure (a chemical structure having a sulfur atom of a thiol group on one end side and an oxygen atom of a hydroxyl group on the other end side) The lone electron pair of the sulfur atom of the thiol group in the connecting structure part is coordinated to the surface of the catalyst particle, and the oxygen atom of the hydroxyl group constitutes the oxide film. Bonded with Si atom, Ti atom or Al atom.
In the present invention, the connecting structure portion that can be selectively bonded to the surface of the catalyst particles is preferably a connecting structure portion derived from 3-mercaptopropyltriethoxysilane (MPTES), but is not limited thereto. Any substance having a thiol group (—SH) and a hydroxyl group (—OH) at both ends can be used. The oxide film is preferably a SiO 2 film, but is not limited to this, and may be TiO 2 or Al 2 O 3 , or may be SiO 2 and a mixed oxide thereof. Good.
本発明の白金触媒における触媒粒子は、白金と白金以外の金属とを含むものであれば良く、従来公知の白金触媒であって良く、例えば、パラジウムを含有するコア粒子と、当該コア粒子の表面に形成された白金シェルとを有する白金コアシェル触媒又は、白金と、パラジウム、コバルト、ニッケル、鉄又は銅との白金合金触媒であることが好ましい。
白金コアシェル触媒である場合、コア及び/又はシェルを生成させる方法は特に制限されず、白金シェルの形成には、外部電源を使用した精密な電位制御と対極や参照極を必要としない、改良型Cu-UPD法を用いることが好ましい。改良型Cu-UPD法とは、Pd/Cコアを、Cuからなる固体が浸漬されたCu2+イオンを含有する酸性水溶液中に投入し、アルゴンや窒素等の不活性ガス雰囲気中で撹拌することで、Pdコア表面にCuからなる単原子膜を形成させる方法である。そして、続いて、得られたPdコア粒子表面のCuをPtと置換するが、このステップは公知の置換めっき法で行うことができる。
The catalyst particles in the platinum catalyst of the present invention may be those containing platinum and a metal other than platinum, and may be a conventionally known platinum catalyst, for example, core particles containing palladium, and the surface of the core particles. A platinum core-shell catalyst having a platinum shell formed on a platinum alloy or a platinum alloy catalyst of platinum and palladium, cobalt, nickel, iron or copper is preferable.
In the case of a platinum core-shell catalyst, the method of generating the core and / or shell is not particularly limited, and the platinum shell is formed with an improved type that does not require precise potential control using an external power source and a counter electrode or reference electrode. It is preferable to use a Cu-UPD method. In the improved Cu-UPD method, a Pd / C core is put into an acidic aqueous solution containing Cu 2+ ions in which a solid made of Cu is immersed, and stirred in an inert gas atmosphere such as argon or nitrogen. In this way, a monoatomic film made of Cu is formed on the surface of the Pd core. Subsequently, Cu on the surface of the obtained Pd core particles is substituted with Pt, and this step can be performed by a known substitution plating method.
尚、パラジウムを含有するコア粒子と、当該コア粒子の表面に形成された白金シェルとを有する白金コアシェル触媒の場合、当該白金コアシェル触媒のPdコア粒子の粒径は3.0 nm〜7.0 nmが適する。粒径3.0 nm未満のPdコア粒子を使用した場合、白金コアシェル触媒の粒径が小さくなり、電位変動による凝集が生じやすくなる問題がある。一方、粒径が7.0 nmを超えると白金コアシェル触媒の粒径が大きくなり、電位変動によって触媒粒子が多孔質化し、ORR活性が高まらない問題がある。なお、Pdコア粒子の粒径は、TEM像から求めた平均粒径、或いはPdの(220)面のX線回折ピークにシェラー式を適用して算出した値を意味している。
このような白金コアシェル触媒のPtシェルの平均的厚みは、単原子層(1 ML相当)〜三原子層(3 ML相当)、すなわち0.3 nm〜0.9 nm程度であることが好ましい。酸素還元触媒として活性を発揮するPt原子は、シェルの最外層(最表面)に位置するPt原子のみであるが、耐食性の観点からPt単原子層では不十分と考えられる。本発明により、Ptシェル原子が再配列して厚膜化することは耐食性の点から重要であり、二原子層〜三原子層のPtシェル厚みが適している。三原子層を超えるPtシェルでは、酸素還元反応に関与しないPt原子が増加し、ORR質量活性の低下を招く。白金コアシェル触媒におけるPtシェルは、Ptのみからなってもよいし、PdとPtが混在していてもよいし、Pt-Pd合金シェルでも良い。またPd以外の異種金属との合金シェルであってもよい。異種金属としては、白金よりも酸化還元電位が低い金属が好ましく、例えば銀(Ag)、銅(Cu)、ニッケル(Ni)、コバルト(Co)が挙げられる。
In the case of a platinum core-shell catalyst having a palladium-containing core particle and a platinum shell formed on the surface of the core particle, the particle size of the Pd core particle of the platinum core-shell catalyst is suitably 3.0 nm to 7.0 nm. When Pd core particles having a particle size of less than 3.0 nm are used, there is a problem that the particle size of the platinum core-shell catalyst becomes small and aggregation due to potential fluctuations is likely to occur. On the other hand, when the particle size exceeds 7.0 nm, the particle size of the platinum core-shell catalyst becomes large, the catalyst particles become porous due to potential fluctuations, and the ORR activity does not increase. The particle diameter of the Pd core particle means an average particle diameter obtained from a TEM image or a value calculated by applying the Scherrer equation to the X-ray diffraction peak of the (220) plane of Pd.
The average thickness of the Pt shell of such a platinum core-shell catalyst is preferably a monoatomic layer (corresponding to 1 ML) to a triatomic layer (corresponding to 3 ML), that is, about 0.3 nm to 0.9 nm. Pt atoms that exhibit activity as an oxygen reduction catalyst are only Pt atoms located in the outermost layer (outermost surface) of the shell, but a Pt monoatomic layer is considered insufficient from the viewpoint of corrosion resistance. According to the present invention, it is important from the viewpoint of corrosion resistance that the Pt shell atoms are rearranged to form a thick film, and a Pt shell thickness of a diatomic layer to a triatomic layer is suitable. In a Pt shell exceeding the triatomic layer, Pt atoms not participating in the oxygen reduction reaction increase, leading to a decrease in ORR mass activity. The Pt shell in the platinum core-shell catalyst may consist of Pt alone, Pd and Pt may be mixed, or a Pt—Pd alloy shell. Further, it may be an alloy shell with a different metal other than Pd. As the dissimilar metal, a metal having a lower redox potential than platinum is preferable, and examples thereof include silver (Ag), copper (Cu), nickel (Ni), and cobalt (Co).
本発明の白金触媒においては、カーボン担体(炭素質材料からなる担体)の表面に上記の触媒粒子が、図7の下側の模式図に示されるようにして分散された状態で担持されていることが好ましく、担体である炭素質材料としては、カーボンブラック、ケッチェンブラック、アセチレンブラック、カーボンナノチューブ等が挙げられる。上記の担体は、比表面積が10〜1000 m2/g程度であることが好ましい。白金触媒は、主に静電的相互作用によって担体の表面に担持されていると考えられるが、より強固に担持させて担体表面からの触媒の脱落を低減するためには、白金触媒と担体との間に化学的結合を形成して担持することもできる。
カーボン担体に担持されたPdコア粒子は公知の合成法によって合成することができる。一例として、塩化パラジウム(PdCl2)、硝酸パラジウム(Pd(NO3)2)、酢酸パラジウム(Pd(CH3COO)2)、塩化パラジウム(II)ナトリウム・三水和物(Na2[PdCl4]・3H2O)、ジニトロジアンミンパラジウム(II)([Pd(NH3)2(NO2)2])等の水溶液、有機溶液、又はそれらの混合溶液中にカーボン担体を共存させ、パラジウムイオンを還元してカーボン担持Pdナノ粒子コアを得る方法がある。
In the platinum catalyst of the present invention, the above catalyst particles are supported in a dispersed state on the surface of a carbon support (support made of a carbonaceous material) as shown in the schematic diagram on the lower side of FIG. Preferably, the carbonaceous material as a carrier includes carbon black, ketjen black, acetylene black, carbon nanotubes and the like. The carrier preferably has a specific surface area of about 10 to 1000 m 2 / g. The platinum catalyst is thought to be supported on the surface of the support mainly by electrostatic interaction. However, in order to reduce the amount of catalyst falling off from the support surface by supporting it more firmly, the platinum catalyst and the support A chemical bond can be formed between and supported.
The Pd core particles supported on the carbon support can be synthesized by a known synthesis method. Examples include palladium chloride (PdCl 2 ), palladium nitrate (Pd (NO 3 ) 2 ), palladium acetate (Pd (CH 3 COO) 2 ), palladium (II) chloride sodium trihydrate (Na 2 [PdCl 4 ] · 3H 2 O), dinitrodiamminepalladium (II) ([Pd (NH 3 ) 2 (NO 2 ) 2 ]), etc. There is a method for reducing carbon to obtain a carbon-supported Pd nanoparticle core.
次に、前記の酸化物被膜によって表面が被覆された状態の触媒粒子がカーボン担体の表面に担持された、本発明の白金触媒を製造するための方法について説明する。
図1には、触媒粒子として、パラジウムを含有するコア粒子と、当該コア粒子の表面に形成された白金シェルとを有する白金コアシェル触媒を使用し、連結化合物として3−メルカプトプロピルトリエトキシシラン(MPTES)を使用し、シリカ被膜を形成させるための化合物としてテトラエトキシシラン(TEOS)を使用した際の、本発明の白金触媒(SH-SiO2 Pt/Pd/C触媒)の製造方法の好ましい一例における合成スキームが示されている。
Next, a method for producing the platinum catalyst of the present invention in which the catalyst particles whose surface is coated with the oxide film is supported on the surface of the carbon support will be described.
In FIG. 1, a platinum core-shell catalyst having palladium-containing core particles and a platinum shell formed on the surface of the core particles is used as catalyst particles, and 3-mercaptopropyltriethoxysilane (MPTES) is used as a linking compound. In a preferred example of the method for producing a platinum catalyst (SH-SiO 2 Pt / Pd / C catalyst) of the present invention when tetraethoxysilane (TEOS) is used as a compound for forming a silica film. A synthetic scheme is shown.
本発明の製造方法における第1の工程は、白金と白金以外の金属とを含む触媒粒子がカーボン担体に担持された触媒を準備し、当該触媒を水溶液中にて分散させる工程であり、一般的には、水‐アルコール混合溶液中に上記の触媒を入れ、超音波スターラーを用いて超音波撹拌分散を行うのが好ましいが、この分散方法は、上記の方法に限定されるものではない。 The first step in the production method of the present invention is a step of preparing a catalyst in which catalyst particles containing platinum and a metal other than platinum are supported on a carbon carrier, and dispersing the catalyst in an aqueous solution. In this case, it is preferable to put the above catalyst in a water-alcohol mixed solution and carry out ultrasonic stirring dispersion using an ultrasonic stirrer, but this dispersion method is not limited to the above method.
本発明の製造方法における第2の工程は、不活性気体存在下にて、上記の工程で得られた分散液にアルカリ剤を添加して当該水溶液をアルカリ性にし(例えばpHを10.5以上となるようにし)、その後、一端側にチオール基を有し、他端側にトリアルコキシシリル基を有する連結化合物を種付け剤として添加して第1の加水分解(アルカリ加水分解)を行う工程であり、一般的には、第1の工程で得られた分散溶液に不活性気体(例えば窒素ガス)を送入しながら、加温(例えば50〜70℃)し、トリエチルアミンやトリメチルアミン等の有機アミン化合物を添加して分散溶液をアルカリ性にした後(例えばpHを10.5以上に調整した後)、3−メルカプトプロピルトリエトキシシラン(MPTES)等の連結化合物を添加し、例えば50〜70℃の温度にて撹拌する。
この工程では、カーボン担体上に担持された触媒粒子の表面に、上記の化学構造を有した連結化合物における一端側に位置するチオール基の硫黄原子の孤立電子対が配位する一方、他端側に位置した基(MPTESの場合にはトリエトキシシリル基)は加水分解を受けて水酸基が生成する(MPTESの場合にはトリヒドロキシシリル基が生成する)。本発明では、上記連結化合物の化学構造によって、当該連結化合物が触媒粒子に対して選択的に配位し、触媒粒子が存在していないカーボン担体の部分にはほとんど付着しない。
In the second step of the production method of the present invention, in the presence of an inert gas, an alkaline agent is added to the dispersion obtained in the above step to make the aqueous solution alkaline (for example, the pH is set to 10.5 or more). And then performing a first hydrolysis (alkali hydrolysis) by adding a connecting compound having a thiol group on one end side and a trialkoxysilyl group on the other end side as a seeding agent. In general, while supplying an inert gas (for example, nitrogen gas) to the dispersion solution obtained in the first step, heating (for example, 50 to 70 ° C.) and organic amine compounds such as triethylamine and trimethylamine are performed. Is added to make the dispersion alkaline (for example, after adjusting the pH to 10.5 or higher), and then a connecting compound such as 3-mercaptopropyltriethoxysilane (MPTES) is added, for example, 5 Stirred at ~70 ℃ of temperature.
In this step, the lone electron pair of the sulfur atom of the thiol group located on one end side of the linking compound having the above chemical structure is coordinated to the surface of the catalyst particles supported on the carbon support, while the other end side The group located at (triethoxysilyl group in the case of MPTES) undergoes hydrolysis to produce a hydroxyl group (in the case of MPTES, a trihydroxysilyl group is produced). In the present invention, due to the chemical structure of the linking compound, the linking compound is selectively coordinated to the catalyst particles and hardly adheres to the portion of the carbon support where no catalyst particles are present.
本発明の製造方法における第3の工程は、上記の第1の加水分解後の分散溶液に、テトラアルコキシシラン化合物、テトラアルコキシチタン化合物又はトリアルコキシアルミニウム化合物を添加して加温し、第2の加水分解を行う工程であり、この工程によって、前記の工程で生成した水酸基と、上記化合物にある一つのアルコキシ基が反応し、前記連結化合物における酸素原子にSi、Ti又はAl原子が結合し、水酸基と反応しなかった残りのアルコキシ基については加水分解を受けて水酸基が生成する。 In the third step of the production method of the present invention, a tetraalkoxysilane compound, a tetraalkoxytitanium compound or a trialkoxyaluminum compound is added to the dispersion solution after the first hydrolysis and heated, It is a step of performing hydrolysis, and by this step, the hydroxyl group generated in the above step reacts with one alkoxy group in the above compound, and Si, Ti or Al atom is bonded to the oxygen atom in the linking compound, The remaining alkoxy group that has not reacted with the hydroxyl group undergoes hydrolysis to form a hydroxyl group.
本発明の製造方法における第4の工程は、上記の第2の加水分解後の触媒を濾別して乾燥させ、非酸化性雰囲気で加熱する工程であり、この工程では、分散溶液から取り出した触媒を、非酸化性雰囲気下、300〜400℃の温度(好ましくは350℃)で加熱することによって、図7の下側の模式図に示されるような、カーボン担体に担持された触媒粒子の表面だけがSiO2成分(前記工程にてテトラアルコキシチタン化合物を添加した場合にはTiO2成分、前記工程にてトリアルコキシアルミニウム化合物を添加した場合にはAl2O3成分)にて被覆され、カーボン担体の、触媒粒子が存在していない部分においては、カーボン担体の表面がそのままの状態で露出した白金触媒が生成する。 The fourth step in the production method of the present invention is a step in which the catalyst after the second hydrolysis is filtered and dried and heated in a non-oxidizing atmosphere. In this step, the catalyst taken out from the dispersion solution is removed. By heating at a temperature of 300 to 400 ° C. (preferably 350 ° C.) in a non-oxidizing atmosphere, only the surface of the catalyst particles supported on the carbon support as shown in the schematic diagram on the lower side of FIG. Is coated with a SiO 2 component (a TiO 2 component when a tetraalkoxytitanium compound is added in the above step, or an Al 2 O 3 component when a trialkoxyaluminum compound is added in the above step), and a carbon carrier In the portion where the catalyst particles do not exist, a platinum catalyst is produced in which the surface of the carbon support is exposed as it is.
本発明では、上記の第4の工程の後に、上記の工程により得られた白金触媒を分散した酸性溶液を調製した後、当該酸性溶液に複数種類の化学種を交互に、一定の持続時間をもって繰り返し送入することによって、白金触媒に対して所定の電位を繰り返し与える工程を行っても良い。当該工程は、白金触媒の製造における後処理工程であり、触媒の活性を向上させるための触媒活性向上処理工程である。当該工程によって、白金よりも低い酸化還元電位を有する異種金属(パラジウム、コバルト、ニッケル、鉄、銅等)の一部が酸化溶出するとともに、触媒粒子の表面では白金原子の再配列が起こり、さらに触媒粒子同士の凝集が抑制される。その結果、触媒のORR面積比活性が高くなり、かつ、電気化学的表面積が維持され、ORR質量活性の高い触媒が得られると考えられている。 In the present invention, after the fourth step, after preparing an acidic solution in which the platinum catalyst obtained by the above step is dispersed, a plurality of kinds of chemical species are alternately added to the acidic solution with a certain duration. A step of repeatedly applying a predetermined potential to the platinum catalyst by repeatedly feeding may be performed. The said process is a post-processing process in manufacture of a platinum catalyst, and is a catalyst activity improvement processing process for improving the activity of a catalyst. By this process, a part of different metals (palladium, cobalt, nickel, iron, copper, etc.) having a redox potential lower than that of platinum are oxidized and eluted, and the rearrangement of platinum atoms occurs on the surface of the catalyst particles. Aggregation of the catalyst particles is suppressed. As a result, it is considered that a catalyst having a high ORR mass activity can be obtained by increasing the ORR area specific activity of the catalyst and maintaining the electrochemical surface area.
上記の触媒活性向上処理工程は、プロトンを含む酸性溶液(例えば、硝酸、硫酸、塩酸、過塩素酸等)に白金触媒を分散し、この分散溶液中に、(I)前記白金触媒の白金の酸化物生成開始電位よりも高い電位を与える化学種を存在させる工程と、(II)前記白金触媒の白金の酸化物還元開始電位よりも低い電位を与える化学種を存在させる工程と、を含む。
上記の工程(I)は、典型的には、(A)前記白金触媒の白金の酸化物生成開始電位よりも高い電位を与える気体(例えば、酸素)を送入する工程である。上記の工程(II)は、典型的には、(B−1)前記白金触媒の白金の酸化物還元開始電位よりも低い電位を与える気体(例えば、水素)を送入する工程、或いは(B−2)前記白金触媒の白金の酸化物還元開始電位よりも低い電位を与える固体(例えば、金属銅)を前記分散溶液中に存在させながら不活性気体(例えば、窒素ガス、アルゴンガス)を送入する工程、である。
In the above catalytic activity improving treatment step, a platinum catalyst is dispersed in an acidic solution containing protons (for example, nitric acid, sulfuric acid, hydrochloric acid, perchloric acid, etc.), and (I) the platinum catalyst in the platinum catalyst is dispersed in the dispersed solution. A step of causing a chemical species to give a potential higher than an oxide generation start potential; and a step of (II) causing a chemical species to give a potential lower than the oxide reduction start potential of platinum of the platinum catalyst to be present.
The above step (I) is typically a step of (A) feeding a gas (for example, oxygen) giving a higher potential than the platinum oxide formation start potential of the platinum catalyst. The above step (II) is typically (B-1) a step of feeding a gas (for example, hydrogen) that gives a potential lower than the platinum oxide reduction start potential of the platinum catalyst, or (B -2) An inert gas (for example, nitrogen gas or argon gas) is sent while a solid (for example, metallic copper) that gives a potential lower than the platinum oxide reduction starting potential of the platinum catalyst is present in the dispersion. Process.
前記工程(A)及び工程(B−1)又は(B−2)は、撹拌しながら行うことが好ましく、工程(A)及び工程(B−1)又は(B−2)は、工程(A)及び工程(B−1)又は(B−2)を交互に複数回(好ましくは20 回〜500 回)繰り返して行うことが好ましい。又、工程(A)及び工程(B−1)の間に、(C)アルゴンガス、窒素ガス等の不活性ガスを送入する工程をさらに含んでいることが好ましく、工程(A)及び工程(B−2)を含む製造方法においても、工程(A)及び工程(B−2)の間に(C)不活性ガスを送入する工程をさらに含んでいることが好ましい。
なお工程(B−2)を採用する場合には、白金触媒を分散した酸性溶液にCu2+イオンを含むことが好ましいが、工程(B−2)実施時以外においては、固体銅を白金触媒分散溶液から除去する。特に、工程(A)実施時には、白金触媒分散溶液中に固体銅が存在してはならない。
The step (A) and the step (B-1) or (B-2) are preferably performed while stirring, and the step (A) and the step (B-1) or (B-2) ) And step (B-1) or (B-2) are preferably repeated alternately several times (preferably 20 times to 500 times). Further, it is preferable that the method further includes (C) a step of feeding an inert gas such as argon gas or nitrogen gas between the step (A) and the step (B-1). Also in the manufacturing method including (B-2), it is preferable to further include a step (C) of feeding an inert gas between the step (A) and the step (B-2).
In addition, when employ | adopting a process (B-2), it is preferable to contain Cu2 + ion in the acidic solution which disperse | distributed the platinum catalyst, However, Solid copper is made into a platinum catalyst except at the time of implementation of a process (B-2). Remove from dispersion. In particular, when the step (A) is performed, solid copper should not be present in the platinum catalyst dispersion solution.
以下、実施例を用いて本発明を具体的に説明するが、本発明は実施例に限定されるものではない。 EXAMPLES Hereinafter, although this invention is demonstrated concretely using an Example, this invention is not limited to an Example.
[実施例1]本発明によるSiO2被覆Pt/Pd/C触媒の作製例
(I)Pd/Cコアの作製
1.4×10-3モルのPd(NO3)2を純水300 mlに溶解させ、この水溶液に0.35 gのカーボン担体(Ketjen Black EC 300J, 比表面積800 m2/g)を超音波分散させ、ホットスタラーで水分を蒸発させてカーボン担体にPd(NO3)2を担持させた。その後、固形物をH2雰囲気中、400℃で1時間還元し、Pd粒子内に吸蔵した水素を除去するためN2雰囲気中、300℃で1時間処理してカーボン担持Pdコア(Pd/C)を得た。
[Example 1] Production example of SiO 2 coated Pt / Pd / C catalyst according to the present invention (I) Production of Pd / C core
1.4 × 10 −3 mol of Pd (NO 3 ) 2 was dissolved in 300 ml of pure water, and 0.35 g of carbon support (Ketjen Black EC 300J, specific surface area 800 m 2 / g) was ultrasonically dispersed in this aqueous solution. Water was evaporated by a hot stirrer and Pd (NO 3 ) 2 was supported on the carbon support. Thereafter, the solid was reduced in an H 2 atmosphere at 400 ° C. for 1 hour, and treated with a carbon-supported Pd core (Pd / C) in an N 2 atmosphere at 300 ° C. for 1 hour in order to remove hydrogen stored in the Pd particles. )
(II)Pd/Cコアの分析
作製したPd/CコアをTEM(日本電子株式会社製、JEM2100F)で観察した結果、カーボン担体に担持されたPd微粒子が確認された。TEM像中の200個のPdコア粒子の直径を測定した結果、平均粒径は4.8 nmであった。また、金属Pdの担持率を熱重量分析(リガク製、Thermo Plus TG-8120)で調べた結果、34.2 wt.%であった。
(II) Analysis of Pd / C core As a result of observing the produced Pd / C core with TEM (JEM2100F, manufactured by JEOL Ltd.), Pd fine particles supported on a carbon support were confirmed. As a result of measuring the diameter of 200 Pd core particles in the TEM image, the average particle size was 4.8 nm. Further, the loading ratio of metal Pd was examined by thermogravimetric analysis (Rigaku, Thermo Plus TG-8120). As a result, it was 34.2 wt.%.
(III)Pd/Cコア上へのPtシェルの形成
(I)で得られたPd/Cコア800 mgを、濃度50 mMのH2SO4と濃度10 mMのCuSO4を含む800 mlの水溶液中に分散させた。Arを500 ml/min.の流量でバブンリングし、Cuシートを水溶液中に共存させた後、5℃で5時間撹拌してPdコア粒子表面にCuシェルを形成した。その後、Cuシートを水溶液から除去し、予めArバブリングして溶存酸素を除去した2モノレーヤー相当のK2PtCl4水溶液を直ちに加え、Cuシェル層をPtシェル層に置換してPt/Pd/C コアシェル触媒を得た。得られたPt/Pd/C コアシェル触媒を濾別し、純水300 ml中に再分散して30分間撹拌した後、濾別した。この操作を3回繰り返してPt/Pd/C コアシェル触媒を洗浄した。その後、大気中60℃のオーブンで6時間乾燥した。
(III) Formation of a Pt shell on the Pd / C core 800 mg of the Pd / C core obtained in (I) was added to an 800 ml aqueous solution containing 50 mM H 2 SO 4 and 10 mM CuSO 4. Dispersed in. Ar was bubbled at a flow rate of 500 ml / min., And the Cu sheet was allowed to coexist in the aqueous solution, and then stirred at 5 ° C. for 5 hours to form a Cu shell on the surface of the Pd core particles. After that, the Cu sheet is removed from the aqueous solution, and a K 2 PtCl 4 aqueous solution equivalent to 2 monolayers, in which the dissolved oxygen is removed by bubbling Ar in advance, is immediately added, and the Cu shell layer is replaced with the Pt shell layer to replace the Pt / Pd / C core shell. A catalyst was obtained. The obtained Pt / Pd / C core-shell catalyst was filtered off, redispersed in 300 ml of pure water, stirred for 30 minutes, and then filtered off. This operation was repeated 3 times to wash the Pt / Pd / C core-shell catalyst. Thereafter, it was dried in an oven at 60 ° C. in the atmosphere for 6 hours.
(IV)Pt/Pd/C触媒の分析
(III)で得られたPt/Pd/C触媒の組成をXRF(SII社製、SEA1200VX)で分析した結果、Pt:Pd = 30.9:69.1 (at.%)であり、金属担持率を熱重量分析(リガク製、Thermo Plus TG-8120)で調べた結果、42.4 wt.%であった。Pdコア粒子径とXRF組成分析値から算出したPtシェル層厚は1.2原子層相当であった。また、触媒粒径をX線回折の(220)面にシェラー式を適用して算出した結果、5.2 nmであった。
(IV) Analysis of Pt / Pd / C catalyst The composition of the Pt / Pd / C catalyst obtained in (III) was analyzed by XRF (SII, SEA1200VX). As a result, Pt: Pd = 30.9: 69.1 (at. As a result of examining the metal loading by thermogravimetric analysis (Rigaku, Thermo Plus TG-8120), it was 42.4 wt.%. The Pt shell layer thickness calculated from the Pd core particle size and XRF composition analysis value was equivalent to 1.2 atomic layers. The catalyst particle size was calculated to be 5.2 nm by applying the Scherrer equation to the (220) plane of X-ray diffraction.
(V)SiO2被覆Pt/Pd/C触媒(本発明品、前処理剤:MPTES)の作製
200 mlの水/エタノール混合溶液(50/50 vol.%)が入ったセパラブルフラスコに(III)で得られたPt/Pd/C触媒100 mgを10分間超音波分散させた。セパラブルフラスコにN2ガスを500 ml/min.の流量でバブリングさせながら水浴を用いて60℃に昇温し、トリエチルアミンを添加して混合液のpHを10.5に調整した。その後、前処理剤として3-メルカプトプロピルトリエトキシシラン(MPTES)を0.0113 mmol添加して1時間撹拌し、その後、シリカ源であるテトラエトキシシラン(TEOS)を1.440 mmol添加して3時間撹拌して加水分解させた。得られた試料を濾別洗浄し、大気中60℃で6時間乾燥した。その後、試料を10% H2/Ar雰囲気下、350℃で2時間熱処理を行って脱水縮合させ、SiO2被覆Pt/Pd/C触媒を得た。
(V) Preparation of SiO 2 coated Pt / Pd / C catalyst (this product, pretreatment agent: MPTES)
In a separable flask containing 200 ml of water / ethanol mixed solution (50/50 vol.%), 100 mg of the Pt / Pd / C catalyst obtained in (III) was ultrasonically dispersed for 10 minutes. While bubbling N 2 gas through the separable flask at a flow rate of 500 ml / min., The temperature was raised to 60 ° C. using a water bath, and triethylamine was added to adjust the pH of the mixture to 10.5. Then, 0.0113 mmol of 3-mercaptopropyltriethoxysilane (MPTES) was added as a pretreatment agent and stirred for 1 hour, and then 1.440 mmol of tetraethoxysilane (TEOS) as a silica source was added and stirred for 3 hours. Hydrolyzed. The obtained sample was washed by filtration and dried in the atmosphere at 60 ° C. for 6 hours. Thereafter, the sample was subjected to heat treatment at 350 ° C. for 2 hours in a 10% H 2 / Ar atmosphere to perform dehydration condensation to obtain a SiO 2 coated Pt / Pd / C catalyst.
(VI)SiO2被覆Pt/Pd/C触媒(本発明品、前処理剤:MPTES)の分析
(V)で得られたSiO2被覆Pt/Pd/C触媒中のシリカ担持量を熱重量分析(リガク製、Thermo Plus TG-8120)で調べた結果、17.0 wt.%であった。また、触媒粒径をX線回折の(220)面にシェラー式を適用して算出した結果、5.6 nmであった。
(VI) Analysis of SiO 2 coated Pt / Pd / C catalyst (present product, pretreatment agent: MPTES) Thermogravimetric analysis of silica loading in the SiO 2 coated Pt / Pd / C catalyst obtained in (V) (Rigaku, Thermo Plus TG-8120) was examined and found to be 17.0 wt.%. The catalyst particle size was calculated by applying the Scherrer equation to the (220) plane of X-ray diffraction. As a result, it was 5.6 nm.
[比較例1]従来法によるSiO2被覆Pt/Pd/C触媒の作製例
(VII)SiO2被覆Pt/Pd/C触媒(従来品、前処理剤:APTES)の作製
200 mlの水/エタノール混合溶液(50/50 vol.%)が入ったセパラブルフラスコに(III)で得られたPt/Pd/C触媒100 mgを10分間超音波分散させた。セパラブルフラスコにN2ガスを500 ml/min.の流量でバブリングさせながら水浴を用いて60℃に昇温し、トリエチルアミンを添加して混合液のpHを10.5に調整した。前処理剤として3-アミノプロピルトリエトキシシラン(APTES)を0.0113 mmol添加して1時間撹拌し、その後、シリカ源であるテトラエトキシシラン(TEOS)を1.440 mmol添加して3時間撹拌して加水分解させた。得られた試料を濾別洗浄し、大気中60℃で6時間乾燥した。その後、試料を10% H2/Ar雰囲気下、350℃で2時間熱処理を行って脱水縮合させ、SiO2被覆Pt/Pd/C触媒を得た。
[Comparative Example 1] Example of production of SiO 2 coated Pt / Pd / C catalyst by conventional method (VII) Production of SiO 2 coated Pt / Pd / C catalyst (conventional product, pretreatment agent: APTES)
In a separable flask containing 200 ml of water / ethanol mixed solution (50/50 vol.%), 100 mg of the Pt / Pd / C catalyst obtained in (III) was ultrasonically dispersed for 10 minutes. While bubbling N 2 gas through the separable flask at a flow rate of 500 ml / min., The temperature was raised to 60 ° C. using a water bath, and triethylamine was added to adjust the pH of the mixture to 10.5. Add 0.0113 mmol of 3-aminopropyltriethoxysilane (APTES) as a pretreatment agent and stir for 1 hour, then add 1.440 mmol of tetraethoxysilane (TEOS) as a silica source and stir for 3 hours to hydrolyze I let you. The obtained sample was washed by filtration and dried in the atmosphere at 60 ° C. for 6 hours. Thereafter, the sample was subjected to heat treatment at 350 ° C. for 2 hours in a 10% H 2 / Ar atmosphere to perform dehydration condensation to obtain a SiO 2 coated Pt / Pd / C catalyst.
(VIII)SiO2被覆Pt/Pd/C触媒(従来品、前処理剤:APTES)の分析
(VII)で得られたSiO2被覆Pt/Pd/C触媒中のシリカ担持量を熱重量分析(リガク製、Thermo Plus TG-8120)で調べた結果、33.0 wt.%であった。また、触媒粒径をX線回折の(220)面にシェラー式を適用して算出した結果、6.1 nmであった。
(VIII) Analysis of SiO 2 coated Pt / Pd / C catalyst (conventional product, pretreatment agent: APTES) Thermogravimetric analysis of silica loading in the SiO 2 coated Pt / Pd / C catalyst obtained in (VII) ( It was 33.0 wt.% As a result of investigation using Thermo Plus TG-8120) manufactured by Rigaku. The catalyst particle size was calculated by applying the Scherrer equation to the (220) plane of X-ray diffraction. As a result, it was 6.1 nm.
[比較例2]熱処理Pt/Pd/C触媒(比較品1)の作製例
(IX)熱処理Pt/Pd/C触媒の作製
(III)で得られたPt/Pd/C触媒をH2/Ar雰囲気下、350℃で2時間熱処理した。
(X)熱処理Pt/Pd/C触媒の分析
(IX)で得られた熱処理したPt/Pd/C触媒の粒径をX線回折の(220)面にシェラー式を適用して算出した結果、6.3 nmであった。
[Comparative Example 2] Preparation Example of Heat-treated Pt / Pd / C Catalyst (Comparative Product 1) (IX) Preparation of Heat-treated Pt / Pd / C Catalyst The Pt / Pd / C catalyst obtained in (III) was converted to H 2 / Ar. Heat treatment was performed at 350 ° C. for 2 hours in an atmosphere.
(X) Analysis of heat-treated Pt / Pd / C catalyst As a result of calculating the particle size of the heat-treated Pt / Pd / C catalyst obtained in (IX) by applying the Scherrer equation to the (220) plane of X-ray diffraction, It was 6.3 nm.
更に比較品2として、未処理Pt/Pd/C触媒(上記(III)で得られたもの)を準備した。 Further, as a comparative product 2, an untreated Pt / Pd / C catalyst (obtained in (III) above) was prepared.
上記の4種類のPt/Pd/C触媒:
(1)未処理のPt/Pd/C触媒(比較品2)、
(2)未処理のPt/Pd/C触媒をH2/Ar雰囲気下で熱処理したもの(比較品1)、
(3)APTESをPt/Pd/C触媒に添加して加水分解を行った後、TEOSを添加して加水分解を行い、さらに加熱下で水素還元したもの(従来品、NH2-SiO2 Pt/Pd/C触媒)、
(4)MPTESをPt/Pd/C触媒に添加して加水分解を行った後、TEOSを添加して加水分解を行い、さらに非酸化性雰囲気で熱処理したもの(本発明品、SH-SiO2 Pt/Pd/C触媒)]
について、電位サイクル耐久性試験(ADT)を実施し、それぞれの触媒の耐久性を評価した。
尚、ADTにおいては、アルゴンガス飽和した、80 ℃、濃度0.1 MのHClO4水溶液に各Pt/Pd/C触媒を浸漬し、可逆水素電極(RHE)に対して0.6 V (3 s)/1.0 V (3 s)の矩形波を、3,000サイクル及び10,000サイクルで電位を付与した。
以下の表1には、上記4種類のPt/Pd/C触媒の製造条件が要約されており、NH2-SiO2 Pt/Pd/C触媒(従来品)と、SH-SiO2 Pt/Pd/C触媒(本発明品)についてはSiO2量が重量%で表されている。
この表1から、SH-SiO2 Pt/Pd/C触媒(本発明品)のSiO2量は、NH2-SiO2 Pt/Pd/C触媒(従来品)のSiO2量の約1/2であることがわかる。
The above four Pt / Pd / C catalysts:
(1) Untreated Pt / Pd / C catalyst (Comparative product 2),
(2) Untreated Pt / Pd / C catalyst heat-treated in H 2 / Ar atmosphere (Comparative product 1),
(3) APTES added to Pt / Pd / C catalyst for hydrolysis, TEOS added for hydrolysis, and hydrogen reduction under heating (conventional product, NH 2 -SiO 2 Pt / Pd / C catalyst),
(4) MPTES added to Pt / Pd / C catalyst for hydrolysis, then TEOS added for hydrolysis, and heat treated in a non-oxidizing atmosphere (this product, SH-SiO 2 Pt / Pd / C catalyst)]
Was subjected to a potential cycle durability test (ADT), and the durability of each catalyst was evaluated.
In the ADT, each Pt / Pd / C catalyst was immersed in an aqueous solution of HClO 4 saturated with argon gas at 80 ° C. and at a concentration of 0.1 M, and 0.6 V (3 s) /1.0 against the reversible hydrogen electrode (RHE). V (3 s) square wave was applied with a potential at 3,000 cycles and 10,000 cycles.
Table 1 below summarizes the production conditions for the above four types of Pt / Pd / C catalysts: NH 2 —SiO 2 Pt / Pd / C catalyst (conventional product), and SH—SiO 2 Pt / Pd. For the / C catalyst (product of the present invention), the amount of SiO 2 is expressed in weight%.
From Table 1, the amount of SiO 2 of the SH—SiO 2 Pt / Pd / C catalyst (product of the present invention) is about ½ of the amount of SiO 2 of the NH 2 —SiO 2 Pt / Pd / C catalyst (conventional product). It can be seen that it is.
図2には、ADT(10,000サイクル)後における上記4種類のPt/Pd/C触媒の形態を観察した際のTEM像が示されており、それぞれのPt/Pd/C触媒についての電気化学的表面積(ECSA)も記載されている。各触媒のECSAは、回転リングディスク電極のGC電極(直径6 mm)上に、Ptが14.1μg/cm2になるよう各触媒を塗布して作用電極を作製し、この作用電極をアルゴンガス飽和した、25 ℃、濃度0.1 MのHClO4水溶液に浸漬し、標準電極に可逆水素電極(RHE)、対極にPt線を使用し、電位幅0.05 V〜1.2 V、電位掃引速度50 mV/sでサイクリックボルタモグラム(CV)を測定し、得られたCVの水素脱着波から算出した。
図2の上側の2つのTEM像は、比較品2(未処理のPt/Pd/C触媒)と、比較品1(H2/Ar雰囲気下で熱処理したPt/Pd/C触媒)についてのADT後のTEM像であり、これら触媒の場合には、形状が丸く単独で存在する触媒粒子に加えて、凝集した触媒粒子も存在していることが確認され、ADTにより触媒粒子が凝集することがわかった。このように触媒粒子同士が凝集するとその電気化学的表面積(ECSA)は減少し、ORR質量活性の低下を招く。
これに対し、図2の下側の2つのTEM像は、従来品(NH2-SiO2 Pt/Pd/C触媒)と、本発明品(SH-SiO2 Pt/Pd/C触媒)についてのADT後のTEM像であり、これら触媒の場合には、ADTによる触媒粒子の凝集が抑制され、ECSA減少も抑制されることが確認された。
Fig. 2 shows TEM images of the four types of Pt / Pd / C catalysts observed after ADT (10,000 cycles). The electrochemical properties of each Pt / Pd / C catalyst are shown in Fig. 2. Surface area (ECSA) is also listed. The ECSA of each catalyst was prepared by applying each catalyst on a rotating ring disk electrode GC electrode (diameter 6 mm) so that Pt was 14.1 μg / cm 2 , and this working electrode was saturated with argon gas. Soaked in 25 ° C, 0.1 M HClO 4 aqueous solution, using reversible hydrogen electrode (RHE) as standard electrode and Pt wire as counter electrode, potential range 0.05 V to 1.2 V, potential sweep rate 50 mV / s A cyclic voltammogram (CV) was measured and calculated from the hydrogen desorption wave of the obtained CV.
The top two TEM images in Fig. 2 show the ADT for Comparative Product 2 (untreated Pt / Pd / C catalyst) and Comparative Product 1 (Pt / Pd / C catalyst heat-treated in H 2 / Ar atmosphere). It is a later TEM image, and in the case of these catalysts, in addition to the catalyst particles having a round shape alone, it is confirmed that there are also agglomerated catalyst particles, and the catalyst particles may be aggregated by ADT. all right. When the catalyst particles agglomerate in this way, their electrochemical surface area (ECSA) decreases, leading to a decrease in ORR mass activity.
On the other hand, the two TEM images on the lower side of FIG. 2 are for the conventional product (NH 2 —SiO 2 Pt / Pd / C catalyst) and the product of the present invention (SH—SiO 2 Pt / Pd / C catalyst). It is a TEM image after ADT, and in the case of these catalysts, it was confirmed that agglomeration of catalyst particles by ADT was suppressed and ECSA decrease was also suppressed.
次に、従来品(NH2-SiO2 Pt/Pd/C触媒)と、本発明品(SH-SiO2 Pt/Pd/C触媒)について、触媒粒子が存在している場所と、触媒粒子が存在していない場所におけるTEM-EDX分析を行った。図3が、従来品のTEM-EDX分析結果を示すチャートであり、図4が、本発明品のTEM-EDX分析結果を示すチャートであり、上側にあるTEM像中の横線で示された位置におけるSi,S,Pd,Ptの強度が、下側のチャートに示されている。
図3のNH2-SiO2 Pt/Pd/C触媒のTEM-EDX分析結果は、Siが、触媒粒子が存在していない場所(カーボン担体)にも存在していることを示しており、カーボン担体の表面もSiO2被膜によって覆われていることが確認された。
これに対し、図4の本発明のSH-SiO2 Pt/Pd/C触媒のTEM-EDX分析結果は、SとSiが、触媒粒子が存在していない場所(カーボン担体)には存在せず、触媒粒子が存在している場所に存在していることを示しており、触媒粒子が存在していないカーボン担体の表面は、SiO2被膜によって被覆されることなく露出していることが確認された。
Next, for the conventional product (NH 2 —SiO 2 Pt / Pd / C catalyst) and the product of the present invention (SH—SiO 2 Pt / Pd / C catalyst), the location of the catalyst particles and the catalyst particles TEM-EDX analysis was performed at a location that did not exist. FIG. 3 is a chart showing the TEM-EDX analysis result of the conventional product, and FIG. 4 is a chart showing the TEM-EDX analysis result of the product of the present invention. The position indicated by the horizontal line in the TEM image on the upper side The intensities of Si, S, Pd, and Pt are shown in the lower chart.
The TEM-EDX analysis results of the NH 2 —SiO 2 Pt / Pd / C catalyst in FIG. 3 indicate that Si is also present at the place where the catalyst particles are not present (carbon support). It was confirmed that the surface of the support was also covered with the SiO 2 coating.
On the other hand, the TEM-EDX analysis result of the SH-SiO 2 Pt / Pd / C catalyst of the present invention in FIG. 4 shows that S and Si are not present where the catalyst particles are not present (carbon support). This indicates that the catalyst particles are present where the catalyst particles are present, and it is confirmed that the surface of the carbon support where the catalyst particles are not present is exposed without being covered with the SiO 2 coating. It was.
図5は、表1に記載される4種類のPt/Pd/C触媒についてのXRDパターンであり、下から順に、未処理のPt/Pd/C触媒(比較品2)、H2/Ar雰囲気下で熱処理したPt/Pd/C触媒(比較品1)、NH2-SiO2 Pt/Pd/C触媒(従来品)、SH-SiO2 Pt/Pd/C触媒(本発明品)である。
図5の結果から、Pt/Pd/C触媒粒子だけがSiO2被膜によって被覆された本発明品の場合には、シラノール基(Si-OH)の脱水縮合反応を進めるための最終工程におけるH2/Ar雰囲気中350℃で2時間の熱処理を行った後の触媒粒径の増加が抑止されるが(粒径5.2 nm→5.6 nm)、従来品の場合には、上記の熱処理によって触媒粒子同士が凝集し、粒径が増加する(粒径5.2 nm→6.1 nm)ことが確認された。
FIG. 5 is an XRD pattern for the four types of Pt / Pd / C catalysts listed in Table 1. From the bottom, the untreated Pt / Pd / C catalyst (Comparative product 2), H 2 / Ar atmosphere. Pt / Pd / C catalyst (Comparative product 1), NH 2 —SiO 2 Pt / Pd / C catalyst (conventional product), and SH—SiO 2 Pt / Pd / C catalyst (present product) heat-treated below.
From the result of FIG. 5, in the case of the present invention product in which only the Pt / Pd / C catalyst particles are coated with the SiO 2 coating, H 2 in the final step for proceeding the dehydration condensation reaction of silanol groups (Si—OH). Although the increase in catalyst particle size after heat treatment at 350 ° C for 2 hours in an Ar atmosphere is suppressed (particle size 5.2 nm → 5.6 nm), Were aggregated and the particle size increased (particle size 5.2 nm → 6.1 nm).
図6は、表1に記載される4種類のPt/Pd/C触媒についてのADTによるECSAの変化を示すグラフであり、グラフの右側には、ADT 10,000サイクル後の各触媒のECSAと、ADT前のECSA値からの低下率が併記されている。
この図6の結果は、第1の加水分解工程にて使用される成分をAPTESからMPTESに変更することにより、約1/2のSiO2量でAPTESと同等以上の優れた耐久性が実現できることを示している。
FIG. 6 is a graph showing changes in ECSA by ADT for the four types of Pt / Pd / C catalysts listed in Table 1. The right side of the graph shows the ECSA of each catalyst after ADT 10,000 cycles and ADT. The rate of decrease from the previous ECSA value is also shown.
The result of FIG. 6 shows that by changing the component used in the first hydrolysis step from APTES to MPTES, excellent durability equivalent to or better than APTES can be realized with about 1/2 SiO 2 amount. Is shown.
図7には、従来のAPTES→TEOS加水分解によるPt系触媒のSiO2被覆状態を示す模式図(上側の図)と、本発明によるMPTES→TEOS加水分解によるPt系触媒のSiO2被覆状態を示す模式図(下側の図)が示されている。
従来の製法により得られたPt系触媒の場合には、触媒粒子の外周面がSiO2被膜によって覆われているために耐久性が向上するが、カーボン担体の表面にも絶縁性のSiO2被膜が存在しているため、電池を組んだ際に抵抗損失が大きく、電池特性を低下させるという欠点がある。一方、本発明の製法を用いて得られたPt系触媒の場合には、SiO2被膜が触媒粒子の外周面を選択的に被覆して耐久性が向上すると同時に、カーボン担体の表面がSiO2被膜によって覆われていないため、電池を組んだ際の抵抗損失が抑制され、電池特性の低下が少ない点でも優れている。
Figure 7 is a schematic diagram showing a SiO 2 coating state of the art APTES → Pt-based catalyst by TEOS hydrolysis and (upper side in the drawing), the SiO 2 coating state of the Pt-based catalyst according to MPTES → TEOS hydrolysis according to the invention A schematic diagram (lower diagram) is shown.
In the case of Pt-based catalyst obtained by the conventional method, although the durability is improved since the outer peripheral surface of the catalyst particles is covered with the SiO 2 film, a carbon support SiO 2 coating of insulative on the surface of Therefore, when the battery is assembled, there is a disadvantage that the resistance loss is large and the battery characteristics are deteriorated. On the other hand, in the case of the Pt-based catalyst obtained by using the production method of the present invention, the SiO 2 coating selectively coats the outer peripheral surface of the catalyst particles to improve durability, and at the same time, the surface of the carbon support is made of SiO 2 Since it is not covered with a film, the resistance loss when the battery is assembled is suppressed, and the battery characteristics are less deteriorated.
本発明の製造方法を用いることによって、優れた耐久性を有するPt/Pd/C触媒を製造することができ、このようなPt/Pd/C触媒は、特に燃料電池における酸素還元反応の触媒として利用することができる。 By using the production method of the present invention, a Pt / Pd / C catalyst having excellent durability can be produced, and such a Pt / Pd / C catalyst is used as a catalyst for an oxygen reduction reaction particularly in a fuel cell. Can be used.
Claims (10)
白金と白金以外の金属とを含む触媒粒子がカーボン担体に担持された触媒を準備し、当該触媒を水溶液中にて分散させる工程と
不活性気体存在下にて、上記工程で得られた分散溶液にアルカリ剤を添加して当該分散溶液をアルカリ性になるようにし、その後、一端側にチオール基を有し、他端側にトリアルコキシシリル基を有する連結化合物を添加して第1の加水分解を行う工程と、
上記加水分解後の分散溶液に、テトラアルコキシシラン化合物、テトラアルコキシチタン化合物又はトリアルコキシアルミニウム化合物を添加して第2の加水分解を行う工程と、
上記加水分解後の触媒を濾別して乾燥させ、非酸化性雰囲気で熱処理する工程
を含むことを特徴とする白金触媒の製造方法。 A method for producing a platinum catalyst for a fuel cell in which catalyst particles containing platinum and a metal other than platinum are supported on the surface of a carbon carrier,
Preparing a catalyst in which catalyst particles containing platinum and a metal other than platinum are supported on a carbon carrier, and dispersing the catalyst in an aqueous solution; in the presence of an inert gas, the dispersion solution obtained in the above step An alkali agent is added to make the dispersion solution alkaline, and then a first compound is added by adding a linking compound having a thiol group at one end and a trialkoxysilyl group at the other end. A process of performing;
A step of performing a second hydrolysis by adding a tetraalkoxysilane compound, a tetraalkoxytitanium compound or a trialkoxyaluminum compound to the dispersion solution after the hydrolysis;
A method for producing a platinum catalyst, comprising a step of filtering and drying the hydrolyzed catalyst and heat-treating it in a non-oxidizing atmosphere.
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Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN111509240A (en) * | 2020-05-19 | 2020-08-07 | 深圳市通用氢能科技有限公司 | Carbon-supported platinum catalyst powder and preparation method and application thereof |
JP2021062362A (en) * | 2019-10-15 | 2021-04-22 | 日揮触媒化成株式会社 | Transition metal carrier covered with substance having micropores and method for producing the same |
CN114026718A (en) * | 2019-06-28 | 2022-02-08 | 可隆工业株式会社 | Fuel cell catalyst, method of manufacturing the same, and membrane-electrode assembly including the same |
Citations (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2005276688A (en) * | 2004-03-25 | 2005-10-06 | Tohoku Techno Arch Co Ltd | Catalyst nano particle |
US20060135359A1 (en) * | 2004-12-22 | 2006-06-22 | Radoslav Adzic | Platinum- and platinum alloy-coated palladium and palladium alloy particles and uses thereof |
JP2008004541A (en) * | 2006-05-25 | 2008-01-10 | Nissan Motor Co Ltd | Electrode material |
JP2010188243A (en) * | 2009-02-17 | 2010-09-02 | Hitachi Ltd | Catalytic material and method of producing the same |
JP2011096476A (en) * | 2009-10-29 | 2011-05-12 | Kazufumi Ogawa | Air-permeable porous electrode, air-permeable separator, fuel cell using them, manufacturing method of them, and vehicle using fuel cell |
JP2015196144A (en) * | 2014-04-02 | 2015-11-09 | トヨタ自動車株式会社 | Method for producing core shell catalyst |
JP2016091878A (en) * | 2014-11-07 | 2016-05-23 | Jxエネルギー株式会社 | Method for manufacturing electrode material, membrane-electrode assembly and fuel cell stack |
-
2016
- 2016-03-18 JP JP2016054844A patent/JP6815590B2/en not_active Expired - Fee Related
Patent Citations (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2005276688A (en) * | 2004-03-25 | 2005-10-06 | Tohoku Techno Arch Co Ltd | Catalyst nano particle |
US20070026294A1 (en) * | 2004-03-25 | 2007-02-01 | Yuzuru Shimazaki | Catalyst nanoparticle |
US20060135359A1 (en) * | 2004-12-22 | 2006-06-22 | Radoslav Adzic | Platinum- and platinum alloy-coated palladium and palladium alloy particles and uses thereof |
JP2008004541A (en) * | 2006-05-25 | 2008-01-10 | Nissan Motor Co Ltd | Electrode material |
JP2010188243A (en) * | 2009-02-17 | 2010-09-02 | Hitachi Ltd | Catalytic material and method of producing the same |
JP2011096476A (en) * | 2009-10-29 | 2011-05-12 | Kazufumi Ogawa | Air-permeable porous electrode, air-permeable separator, fuel cell using them, manufacturing method of them, and vehicle using fuel cell |
JP2015196144A (en) * | 2014-04-02 | 2015-11-09 | トヨタ自動車株式会社 | Method for producing core shell catalyst |
JP2016091878A (en) * | 2014-11-07 | 2016-05-23 | Jxエネルギー株式会社 | Method for manufacturing electrode material, membrane-electrode assembly and fuel cell stack |
Cited By (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN114026718A (en) * | 2019-06-28 | 2022-02-08 | 可隆工业株式会社 | Fuel cell catalyst, method of manufacturing the same, and membrane-electrode assembly including the same |
JP2022534016A (en) * | 2019-06-28 | 2022-07-27 | コーロン インダストリーズ インク | Fuel cell catalyst, manufacturing method thereof, and membrane electrode assembly including the same |
JP7286809B2 (en) | 2019-06-28 | 2023-06-05 | コーロン インダストリーズ インク | Fuel cell catalyst, manufacturing method thereof, and membrane electrode assembly including the same |
EP3993111A4 (en) * | 2019-06-28 | 2024-01-24 | Kolon Industries, Inc. | Fuel cell catalyst, manufacturing method therefor, and membrane-electrode assembly including same |
CN114026718B (en) * | 2019-06-28 | 2024-03-01 | 可隆工业株式会社 | Fuel cell catalyst, method of manufacturing the same, and membrane-electrode assembly including the same |
JP2021062362A (en) * | 2019-10-15 | 2021-04-22 | 日揮触媒化成株式会社 | Transition metal carrier covered with substance having micropores and method for producing the same |
JP7449123B2 (en) | 2019-10-15 | 2024-03-13 | 日揮触媒化成株式会社 | Transition metal support coated with a material having micropores and its manufacturing method |
CN111509240A (en) * | 2020-05-19 | 2020-08-07 | 深圳市通用氢能科技有限公司 | Carbon-supported platinum catalyst powder and preparation method and application thereof |
CN111509240B (en) * | 2020-05-19 | 2022-09-20 | 深圳市通用氢能科技有限公司 | Carbon-supported platinum catalyst powder and preparation method and application thereof |
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