CN109092315B

CN109092315B - Catalyst for preparing tetrahydronaphthalene through naphthalene selective catalytic hydrogenation, and preparation method and application thereof

Info

Publication number: CN109092315B
Application number: CN201810798514.4A
Authority: CN
Inventors: 孙鸣; 苏小平; 张勇; 赵阳坤; 么秋香; 郝青青; 马晓迅
Original assignee: Northwestern University
Current assignee: Northwestern University
Priority date: 2018-07-19
Filing date: 2018-07-19
Publication date: 2021-04-27
Anticipated expiration: 2038-07-19
Also published as: CN109092315A

Abstract

Compared with naphthalene, the tetrahydronaphthalene belongs to a high-value product, and the method can realize high added value and deep processing fine utilization of downstream products of coal tar. The method adopts a high-temperature high-pressure reaction kettle, and finds that the oxidation state catalyst has obvious effect on preparing the tetrahydronaphthalene by the selective hydrogenation of the naphthalene for the first time. Wherein the hydrogenation catalyst used consists of: with gamma-Al₂O₃As carrier, Ni and Mo as active metals, Al₂O₃The content of the carrier is 70-90%, the total load of Ni and Mo is 12-36%, and the load ratio of Ni to Mo is 1:23-8: 16. The invention provides a high additional utilization method of coal tar downstream products which has been ignored by people all the time, and the used oxidation state catalyst has the advantages of simple preparation, easy storage, good recycling stability, easy regeneration and the like.

Description

Catalyst for preparing tetrahydronaphthalene through naphthalene selective catalytic hydrogenation, and preparation method and application thereof

Technical Field

The invention belongs to the field of deep processing of coal tar, and particularly relates to a catalyst for preparing tetrahydronaphthalene through naphthalene selective catalytic hydrogenation, and a preparation method and application thereof.

Background

Compared with petroleum resources, coal tar resources have irreplaceability; coal tar is used as an important resource to protect abroad. At present, the domestic coal tar processing technology is relatively backward, the deep processing is insufficient, and the method only stays in the rough processing stage. The coal tar is exported, and the return sale phenomenon of the processed coal tar products is serious, so that China suffers great economic loss.

Naphthalene is an important chemical raw material as a bicyclic aromatic hydrocarbon; the yield can be used as a mark for measuring the development level of organic chemical engineering. The naphthalene content in the coal tar is about 10 percent, and industrial naphthalene and refined naphthalene can be obtained through processes of distillation cutting, cooling crystallization, filtering drying and the like.

Tetrahydronaphthalene belongs to a hydrogenation intermediate of naphthalene and is an important hydrogen donor solvent; the method is widely applied to the process research of direct coal liquefaction, coal pitch hydrogenation, biomass liquefaction and the like. Compared with the prices of naphthalene (500g, 180 yuan) and decahydronaphthalene (250mL, 69.6 yuan), tetrahydronaphthalene (250mL, 695 yuan) is obviously a high-value product. Similar to polycyclic aromatic hydrocarbons such as phenanthrene and pyrene, the value of the product can be improved by preparing corresponding intermediates through partial hydrogenation.

Therefore, the research on the preparation of high value-added products by the partial selective hydrogenation of the polycyclic aromatic hydrocarbon can generate objective economic value on one hand and promote the deep processing and the fine development of the coal tar on the other hand.

At present, the naphthalene hydrogenation catalyst uses more noble metals, transition metal sulfides, reduced transition metals, skeleton nickel and the like. Wherein the noble metal is expensive and has poor sulfur resistance; the reduced transition metal has high preparation cost, difficult storage, harsh preparation conditions of the framework nickel and the like, and is not preferable.

At present, the general research aims at obtaining high hydrogenation performance, and the selective catalytic hydrogenation for preparing the tetrahydronaphthalene with high added value is ignored; meanwhile, the morphology of the catalyst is generally three: most of the coal tar hydrogenation catalyst and the aromatic hydrogenation field are sulfuration state catalysts, but experiments show that the oxidation state catalyst also has hydrogenation performance, and related reports are not seen.

Disclosure of Invention

In order to overcome the problems in the prior art, the invention aims to provide a catalyst for preparing tetrahydronaphthalene by naphthalene selective catalytic hydrogenation, and a preparation method and application thereof.

In order to achieve the purpose, the invention adopts the following technical scheme:

the catalyst for preparing tetrahydronaphthalene by naphthalene selective catalytic hydrogenation comprises a carrier and an active component, wherein the carrier is SiO₂、TiO₂、Al₂O₃One or a mixture of more of HY and HZSM-5; the active component is one or more metals of Co, Mo, Ni and W; the loading amount of the oxide of the active component is 12-36%.

Hair brushIn a further development, the support is Al₂O₃。

The invention is further improved in that the active components are Ni and Mo.

The invention is further improved in that the loading of the oxide of the active component is 18-30%.

The invention is further improved in that NiO and MoO are adopted when active components are Ni and Mo₃The load ratio of (A) is 1:23-8: 36.

The invention is further improved in that NiO and MoO are adopted when active components are Ni and Mo₃The load ratio of (A) is 2:22-4: 20.

A preparation method of a catalyst for preparing tetrahydronaphthalene by naphthalene selective catalytic hydrogenation comprises the steps of loading active components on a catalyst carrier by an isometric impregnation method, carrying out ultrasonic treatment and standing, drying and then roasting to obtain the catalyst; wherein the roasting temperature is 400-600 ℃.

The further improvement of the invention is that the roasting temperature is 450-550 ℃.

Application of catalyst in reaction for preparing tetrahydronaphthalene by selective hydrogenation of naphthalene, initial H of reaction₂The pressure is 2-10MPa, the reaction temperature is 160-240 ℃, and the reaction time is 2-10 h.

A further development of the invention is that the initial H of the reaction₂The pressure is 6-8MPa, the reaction temperature is 180-220 ℃, and the reaction time is 6-8 h.

Compared with the prior art, the invention has the following beneficial effects:

compared with a vulcanized catalyst and a reduced catalyst, the transition metal oxidation catalyst provided by the invention is simple to prepare, low in cost, easy to store and convenient to regenerate. The method adopts the catalyst to prepare the tetrahydronaphthalene in a high-temperature high-pressure reaction kettle under proper reaction conditions, and can realize high naphthalene conversion rate (95.62%) and tetrahydronaphthalene selectivity (99.75%). The catalyst adopted by the method has good reusability, the selectivity of the tetrahydronaphthalene is basically unchanged after being reused for 7 times, the selectivity is close to 100%, and the yield can be stabilized at 66%. Make up the defects of deep processing and fine development of the coal tar and realize high added value utilization of downstream products of the coal tar.

Furthermore, the active component of the catalyst used in the invention is Ni-Mo bimetal, wherein Ni has extremely strong hydrogenation activity, Mo has high selectivity of tetrahydronaphthalene, and the Ni-Mo bimetal has synergistic effect and can play the roles of high activity of Ni and high selectivity of Mo at the same time. Through XPS characterization, NiO and Ni are presumed₂O₃And Al₂(MoO₄)₃The phase mainly plays a role in hydrogenation activity, MoO₂And MoO₃The phase acts primarily as a selectivity for tetrahydronaphthalene.

The preparation method of the catalyst is simple and easy to realize.

The method takes naphthalene (primary product of coal tar) as a raw material, and takes selective partial hydrogenation to prepare tetrahydronaphthalene with high added value as a target; the oxidation state NiO-MoO is found for the first time₃/γ-Al₂O₃The catalyst is suitable for preparing tetrahydronaphthalene by naphthalene selective hydrogenation, shows good catalytic hydrogenation performance and high selectivity, and has the advantages of easy preparation, good recycling stability, convenient regeneration, easy storage and the like.

Drawings

FIG. 1 is a network diagram of a naphthalene hydrogenation reaction.

FIG. 2 is a graph showing the results of different catalysts for catalytic hydrogenation of naphthalene to tetrahydronaphthalene. Wherein A is oxidation state Ni-Mo/Al₂O₃B is reduced Ni-Mo/Al₂O₃C is sulfurized Ni-Mo/Al₂O₃。

FIG. 3 shows different forms of Ni-Mo/gamma-Al₂O₃XRD pattern of the catalyst.

FIG. 4 shows different forms of Ni-Mo/gamma-Al₂O₃BET diagram of the catalyst. Wherein (a) is N₂The adsorption and desorption curve, and (b) the pore size distribution.

FIG. 5 shows different forms of Ni-Mo/γ -Al₂O₃TPD profile of the catalyst.

Figure 6 is a graph of results of different metal loadings on naphthalene conversion and tetrahydronaphthalene selectivity.

FIG. 7 is a graph of the results of nickel molybdenum loading ratio versus naphthalene conversion and tetrahydronaphthalene selectivity.

FIG. 8 is a graph showing the results of different loading patterns on naphthalene conversion and tetrahydronaphthalene selectivity.

FIG. 9 is a graph of the results of repeated use of the catalyst in an oxidized state.

FIG. 10 is an XPS plot of oxidized catalyst after repeated use. Wherein (a) is Mo3d, and (b) is Ni 2P.

FIG. 11 is a TEM image of the catalyst in an oxidized state after repeated use. Wherein, (a) is fresh catalyst, (b) is catalyst used repeatedly, and (c) is catalyst used repeatedly for seven times.

FIG. 12 shows Al prepared by the present invention₂O₃XRD pattern of the support. Wherein (a) is Al prepared by precipitation method₂O₃And (b) is Al prepared by a sol-gel method₂O₃。

Detailed Description

The present invention is further described with reference to the following examples, which are not intended to limit the scope of the present invention.

The catalyst for preparing tetrahydronaphthalene by naphthalene selective catalytic hydrogenation comprises a carrier and an active component, wherein the carrier is SiO₂、TiO₂、Al₂O₃One or a mixture of more of HY and HZSM-5; the active component is one or more metals of Co, Mo, Ni and W; the loading amount of the oxide of the active component is 12-36%, namely the mass loading amount of the oxide of the active component, for example, the oxide of Co is cobaltous oxide, the oxide of Mo is molybdenum trioxide, the oxide of Ni is nickel oxide, and the oxide of W is tungsten trioxide.

Preferably, the loading (mass) of the active component oxide is 18-30%.

Preferably, the carrier is Al₂O₃。

Preferably, the active components are Ni and Mo. NiO and MoO when the active components are Ni and Mo₃The load ratio (mass ratio) of (A) is 1:23 to 8: 16. Preferably, NiO and MoO₃The load ratio (mass ratio) of (A) is 2:22-4: 20.

The preparation method of the catalyst comprises the following steps: loading an active component on a catalyst carrier by adopting an isometric impregnation method, carrying out ultrasonic treatment and standing, drying and roasting to obtain a catalyst; wherein the roasting temperature is 400-600 ℃. Preferably, the temperature of calcination is 450-.

When the active components are two of Co, Mo, Ni and W, the loading mode is one-step impregnation loading or step-by-step impregnation loading, and the one-step impregnation loading is preferred.

Referring to fig. 1, the catalyst is applied to the reaction of preparing tetrahydronaphthalene by naphthalene selective hydrogenation. Initial H of reaction₂The pressure is 2-10MPa, the reaction temperature is 160-240 ℃, and the reaction time is 2-10 h.

Preferably, the initial H of the reaction₂The pressure is 6-8MPa, the reaction temperature is 180-220 ℃, and the reaction time is 6-8 h.

The activity evaluation of the catalyst is carried out on a BFK-0.08L high-temperature high-pressure reaction kettle (Wihaibo Sharp Industrial and mechanical Co., Ltd.), the reactant is 20g of a normal hexane solution containing naphthalene, the mass content of the naphthalene in the normal hexane solution is 5%, and the addition amount of the catalyst is 2 g. The product detection adopts a BEIFEN-3420A gas chromatograph, the sample volume is 0.5 mu L, the box temperature is 165 ℃, the atomizer temperature is 250 ℃, the FID detector temperature is 220 ℃, and the product is quantified by an area normalization method.

The Ni salt in the invention is NiNO₃·6H₂O、NiCl₂·6H₂O、NiCO₃、Ni(CH₃COO)₂·4H₂O、Ni(CO)₄Wherein Mo salt is (NH)₄)₆Mo₇O₂₄·4H₂O、M℃l₅One kind of (1).

Example 1

NiO capacity of 4 percent, MoO₃The load of the NiO-MoO is 20 percent₃/γ-Al₂O₃The preparation of (1): adopting an equal volume impregnation method to add a certain amount of Ni salt (NiNO)₃·6H₂O) and Mo salt ((NH)₄)₆Mo₇O₂₄·4H₂O) adding a certain amount of distilled water to prepare a solution; impregnated in gamma-Al₂O₃Stirring uniformly on a carrier, performing ultrasonic treatment for half an hour, and standing at room temperature for 12 hours; in-line with the aboveDrying at 120 deg.C for 4 hr, and calcining at 500 deg.C for 4 hr; the oxidation state of 4 percent NiO-20 percent MoO can be obtained₃/γ-Al₂O₃。

Comparative example 1

Reduced Ni-Mo/gamma-Al₂O₃The preparation of (1): in a tube furnace, the Ni-Mo/gamma-Al in an oxidized state is₂O₃The catalyst was reduced under the following conditions: heating from 40 ℃ to 120 ℃ at the heating rate of 5 ℃/min and keeping for 1 h; heating to 400 ℃ at the heating rate of 5 ℃/min and keeping for 1 h; the temperature is raised to 500 ℃ at a heating rate of 1 ℃/min and kept for 3 h. H₂The flow rate was calibrated to 200mL/min using a soap film flow meter.

Comparative example 2

Sulfurized Ni-Mo/gamma-Al₂O₃The preparation of (1): in tube furnaces, using CS₂Wet sulfurizing to oxidize Ni-Mo/gamma-Al₂O₃The catalyst was sulfided as follows: heating from 40 ℃ to 170 ℃ at a heating rate of 10 ℃/min, and keeping at 170 ℃ for 1 h; raising the temperature to 230 ℃ at the heating rate of 10 ℃/min, and keeping the temperature at 230 ℃ for 2 h; heating to 280 ℃ at the heating rate of 10 ℃/min, and keeping at 280 ℃ for 2 h; heating to 320 ℃ at the heating rate of 10 ℃/min, and keeping the temperature at 320 ℃ for 2 h; heating to 360 deg.C at a heating rate of 10 deg.C/min, and maintaining at 360 deg.C for 2 h; h₂The flow rate was calibrated to 40mL/min using a soap film flow meter.

The three morphology catalysts prepared in example 1, comparative example 1 and comparative example 2 were charged into a high temperature high pressure reactor under the following reaction conditions: the reaction temperature is 200 ℃, the reaction time is 8H, and the reaction is started by H₂The effect of the catalyst on the preparation of tetrahydronaphthalene by catalytic hydrogenation of naphthalene was examined by using 20g of a 5% naphthalene n-hexane solution as a reaction raw material and 2g of the catalyst under a pressure of 6MPa, and the results are shown in FIG. 2. As can be seen from FIG. 2, the sulfided Ni-Mo/γ -Al₂O₃The catalyst has the highest conversion rate of naphthalene and high hydrogenation activity, and the product mainly comprises decalin; reduced Ni-Mo/gamma-Al₂O₃The catalyst has intermediate conversion rate, selectivity and yield of naphthalene and oxidation state Ni-Mo/gamma-Al₂O₃The catalyst has the highest selectivity and yield of the selective hydrogenation of naphthalene to generate tetrahydronaphthalene, and is most suitable for preparing the tetrahydronaphthalene from the naphthaleneA catalyst for naphthalene.

Examples 2 to 6 are the effect of metal loading.

Example 2

The catalyst with the nickel-molybdenum loading of 12% is prepared by adopting a one-step impregnation method (wherein the mass ratio of nickel oxide to molybdenum oxide is 1: 5).

Example 3

The difference from example 2 is that the nickel molybdenum loading was 18%.

Example 4

The difference from example 2 is that the nickel molybdenum loading was 24%.

Example 5

The difference from example 2 is that the nickel molybdenum loading was 30%.

Example 6

The difference from example 2 is that the nickel molybdenum loading was 36%.

The effect of different metal loading on the hydrogenation of naphthalene to prepare tetrahydronaphthalene of the catalysts prepared in examples 2 to 6 was examined under the conditions of initial reaction pressure of 6MPa, temperature of 200 ℃ and time of 8h, and the result is shown in FIG. 6. As can be seen from fig. 6, the conversion of naphthalene was very low with little conversion at a metal loading of 12%; the conversion rate of naphthalene is gradually increased along with the increase of the loading amount, and the loading limit is reached when the loading amount is 36 percent; when the loading amount is 24 percent, the conversion rate of the naphthalene is 95.62 percent, and the selectivity of the tetrahydronaphthalene is 99.75 percent.

Examples 1, 7 to 10 are examples for examining the influence of different nickel-molybdenum loading ratios

Example 7

The Ni/Mo loading ratio in example 1 was 1:4, which is different from example 1 in that the loading ratio of nickel oxide and molybdenum oxide was 1: 23.

Example 8

The difference from example 1 is that the loading ratio of nickel oxide to molybdenum oxide is 2: 22.

Example 9

The difference from example 1 is that the loading ratio of nickel oxide and molybdenum oxide is 6: 18.

Example 10

The difference from example 1 is that the loading ratio of nickel oxide to molybdenum oxide is 8: 16.

The total loading amount of the metal is constant, and different metal loading ratios can have great influence on the performance of the catalyst. FIG. 7 shows the effect of different Ni/Mo loading ratios (mass ratio of nickel oxide to molybdenum oxide) on the naphthalene conversion and the tetrahydronaphthalene selectivity under the conditions of initial pressure of 6MPa, temperature of 200 ℃ and time of 8 h. As can be seen from FIG. 7, the hydrogenation activity of the catalyst was continuously improved with the increase of the Ni content, and naphthalene was almost completely converted when the Ni/Mo loading ratio reached 8: 16; but the proper amount of Mo content can ensure the selectivity of the tetrahydronaphthalene, and the catalyst is the most suitable catalyst for preparing the tetrahydronaphthalene by naphthalene hydrogenation when the Ni/Mo loading ratio is 4: 20.

Examples 1, 11 and 12 are examples for examining the influence of the load mode

Example 1 4% NiO-20% MoO prepared for one-step impregnation₃/γ-Al₂O₃A catalyst.

Example 11

The step-by-step impregnation method is divided into two methods, one method comprises the steps of firstly impregnating nickel nitrate and then impregnating ammonium molybdate according to the step of the embodiment 1; i.e. impregnation of Ni followed by impregnation of Mo.

Example 12

The other steps were not changed except that the impregnation sequence of nickel nitrate and ammonium molybdate was reversed. Namely, Mo is impregnated first and then Ni is impregnated.

The results of example 1, example 11 and example 12 are shown in FIG. 8. As can be seen from FIG. 8, the catalyst obtained by the one-step impregnation method is most suitable for a system for preparing tetrahydronaphthalene by naphthalene hydrogenation. In the catalytic result of the catalyst by the one-step impregnation method, the conversion rate of naphthalene and the selectivity of tetrahydronaphthalene are both high, the activity of the catalyst for impregnating Ni first and then Mo step by step is relatively low, and the hydrogenation activity of the catalyst for impregnating Mo first and then Ni step by step is high. This is probably because the hydrogenation activity of nickel is stronger and the activity of molybdenum is lower, and when molybdenum is loaded on the outer surface in the step-by-step impregnation, the reaction activity of the catalyst is reduced; when nickel is loaded on the outer surface, the hydrogenation activity of the catalyst is high, so that the naphthalene is easy to be deeply hydrogenated to generate decahydronaphthalene.

Example 13 reusability of catalyst

The oxidation state prepared in example 1 was from 4% NiO to 20% MoO₃/γ-Al₂O₃The catalyst is reused at 200 ℃, 7MPa and 8 h. The results are shown in FIG. 9. As can be seen from fig. 9, as the number of times of repeated use increases, the conversion rate of naphthalene decreases first and then remains stable, the selectivity of tetrahydronaphthalene gradually increases to 100%, and the yield of tetrahydronaphthalene can be stabilized at 66% after three times of repeated use.

To find out Ni-Mo/gamma-Al₂O₃The variation of active components of the catalyst in the process of repeated use is carried out, XPS characterization is carried out on the catalyst after repeated use, the result is shown in figure 10, and as can be seen from figure 10, Mo has four forms which are respectively MoO₂、MoO₃、Mo⁺⁵、Al₂(MOO₄)₃(ii) a The existence form of Ni is mainly NiO, Ni₂O₃And NiAl₂O₄. The XPS peak of the catalyst after repeated use shifts overall to a lower binding energy compared to the fresh catalyst, indicating that reduction of the valence state occurs during repeated use. The most obvious variation is Al₂(MOO₄)₃Disappearance of the phases.

A TEM image of the catalyst after its repeated use is shown in fig. 11, and it can be seen from fig. 11 that the active metal shows a typical layered structure, has a size in the range of 4 to 12nm, and is uniformly dispersed on the catalyst support. The black dots in the figure represent the active metal in the catalyst channels. As the number of reuses increases, the black spots become less, indicating that the active sites decrease during the reuse, which may be the cause of the decrease in hydrogenation performance after the catalyst is reused.

Based on the characterization analysis and experimental results, the Ni-Mo bimetal has a synergistic effect, and can simultaneously exert the high activity of Ni and the high selectivity of Mo. Wherein NiO, Ni₂O₃And Al₂(MoO₄)₃The phase mainly plays a role in hydrogenation activity, MoO₂And MoO₃The phase acts primarily as a selectivity for tetrahydronaphthalene.

Example 14Al₂O₃Preparation of the support

Al in the invention₂O₃The support is prepared by the following precipitation method or by a sol-gel method:

precipitation method for preparing Al₂O₃: separately weighing AlCl by using an analytical balance₃·6H₂Putting O powder and NaOH solid (the mass ratio is 2:1) into a beaker, and adding a proper amount of deionized water to completely dissolve the O powder and the NaOH solid. Slowly add the NaOH solution to the AlCl along the glass rod₃Stirring the solution to obtain white precipitate Al (OH)₃Vacuum filtering the obtained precipitate, washing with hot deionized water for 3 times to obtain block precipitate, drying the precipitate in a 120 deg.C oven for 4 hr, and roasting in a muffle furnace at 600 deg.C, 700 deg.C, 800 deg.C and 900 deg.C for 4 hr to obtain white powder Al₂O₃. The powder is ground, tableted to shape the carrier, to increase its mechanical strength, and screened with a standard sieve of 80-120 mesh.

Preparation of Al by sol-gel method₂O₃: respectively preparing 0.2mol/L Al (NO)₃)₃Solution 300mL, 2mol/L (NH)₄)₂CO₃200mL of solution in prepared Al (NO)₃)₃60 drops of Triton X-100 dispersant are added dropwise to the solution and stirred, during which time (NH) is slowly added₄)₂CO₃Stirring the solution until the pH is 9 (about 60mL of ammonium carbonate solution is added), aging for half an hour, aging for two hours, filtering the obtained solution in a vacuum filter flask, washing the solution with hot distilled water for 3 times, drying the obtained massive precipitate, refluxing the dried massive precipitate in n-butanol for 2 hours (mass ratio of 1:20), drying the dried massive precipitate in a 120 ℃ oven for 4 hours after refluxing, and roasting the dried massive precipitate in a muffle furnace at 800 ℃, 900 ℃, 1000 ℃ and 1100 ℃ for 4 hours respectively to obtain white particles of gamma-Al₂O₃. The granules are ground, tableted to shape the carrier, to increase its mechanical strength, and screened through a standard sieve of 80-120 mesh.

Prepared Al₂O₃The XRD pattern of the carrier is shown in fig. 12, and it can be seen from fig. 12 that Al appears at 37 °, 39 °, 46 ° and 69 ° 2 θ ═ c₂O₃Characteristic peak of (2). With Al synthesized by precipitation₂O₃Compared with Al prepared by a sol-gel method₂O₃The XRD pattern of (a) shows relatively sharp and intense peaks, indicating high crystallinity and large grain size, consistent with BET results. When the roasting temperature is more than 1000 ℃, Al prepared by a precipitation method₂O₃alpha-Al appears₂O₃(2 θ 35 °,36 °,43 °,57 °,69 °) and θ -Al₂O₃(2 θ ═ 37 °,53 °,68 °). Indicating that the carriers had different crystalline phases resulting in differences in their catalytic hydrogenation properties.

4% NiO and 20% MoO₃In the Al prepared above₂O₃On a support, the preparation is described in example 1. The prepared catalyst is subjected to naphthalene hydrogenation experiments at 200 ℃, 6MPa and 8 h. The results are shown in tables 1 and 2, respectively.

TABLE 1 precipitation method of Al₂O₃Effect of vector on naphthalene conversion and Tetrahydronaphthalene selection

As can be seen from Table 1, it is compatible with commercial Al₂O₃Al prepared by precipitation method compared with carrier₂O₃The hydrogenation performance of the catalyst used as a carrier is very low. The weaker activity is associated with the total acid content and less medium-weak acid distribution, with too large pore size and low specific surface area, as indicated by TPD, BET characterization.

TABLE 2 Sol-gel method Al₂O₃Effect of vector on naphthalene conversion and Tetrahydronaphthalene selection

As can be seen from Table 2, it is compatible with commercial Al₂O₃Compared with a carrier, the Al prepared by adopting a sol-gel method₂O₃The catalyst used as the carrier has better hydrogenation performance, and the highest yield can reach 98.99.

Claims

1. the application of a catalyst for preparing tetrahydronaphthalene by selective catalytic hydrogenation of naphthalene in the reaction of preparing tetrahydronaphthalene by selective hydrogenation of naphthalene, is characterized in that, comprises carrier and active component, and described carrier is SiO ₂ , TiO ₂ , Al ₂ O ₃ , HY, HZSM-5 one or more of the mixture; the active component is one or more metals in Co, Mo, Ni, W; The mass loading of oxides is 12%-36%; the initial H pressure of the reaction is _2-10MPa , the reaction temperature is 160-240 ^o C, and the reaction time is 2-10h, the oxidation state catalyst is used in the reaction, compared with the reduction state and sulfur state catalysts, and oxidized state catalysts have high tetralin selectivity.

2. the application of a kind of catalyst for preparing tetralin by selective catalytic hydrogenation of naphthalene according to claim 1 in the reaction of preparing tetralin by selective hydrogenation of naphthalene, it is characterized in that, the carrier is Al ₂ O ₃ .

3. the application of a kind of catalyst for preparing tetralin by selective catalytic hydrogenation of naphthalene according to claim 1 in the reaction of preparing tetralin by selective hydrogenation of naphthalene, it is characterized in that, the oxide of active component The mass loading is 18%-30%.

4. the application of a kind of catalyst for preparing tetralin by selective catalytic hydrogenation of naphthalene according to claim 1 in the reaction of preparing tetralin by selective hydrogenation of naphthalene, it is characterized in that, active component is Ni and For Mo, the loading mass ratio of NiO to MoO is ₁ :23-8:36.

5. the application of a kind of catalyst for preparing tetralin by selective catalytic hydrogenation of naphthalene according to claim 1 and 4 in the reaction of preparing tetralin by selective hydrogenation of naphthalene, it is characterized in that, active component is When Ni to Mo, the loading mass ratio of NiO to MoO ₃ is 2:22-4:20.

6. the application of the catalyst for preparing tetrahydronaphthalene by selective catalytic hydrogenation of naphthalene according to claim 1 in the selective hydrogenation of naphthalene to prepare the application of tetrahydronaphthalene, it is characterized in that, adopt equal volume impregnation method to make active group The catalyst is sub-loaded on the catalyst carrier, ultrasonicated, allowed to stand, dried and then calcined to obtain a catalyst; wherein, the calcination temperature is 400-600 ^℃ .

7. the application of the catalyst for preparing tetralin by selective catalytic hydrogenation of naphthalene according to claim 6 in the reaction of preparing tetralin by selective hydrogenation of naphthalene, it is characterized in that, the temperature of roasting is 450-550 ^℃ C.

8. the application of the catalyst for preparing tetrahydronaphthalene by selective catalytic hydrogenation of naphthalene according to claim 7 in the reaction of selective hydrogenation of naphthalene to prepare tetrahydronaphthalene, it is characterized in that, the initial H of reaction _The pressure is 6 -8MPa, the reaction temperature is 180-220 ^o C, and the reaction time is 6-8h.