JP2000262907A - Integrated catalyst and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a catalyst which effectively develops activity for a plurality of substances of different kinds at a time. SOLUTION: This integrated catalyst consists of catalyst unit groups containing a large number of catalyst units of a plurality of kinds. The catalyst units aggregate in a nanometer level to form the catalyst unit group. Each catalyst unit of a plurality of kinds has the individual catalytic function, and at least one kind of catalyst unit is selected to be able to complement the catalytic function of at least one of other kinds of catalytic units. Further, each catalyst unit of the plurality of kinds consists of, for example, a metal oxide and a metal element. In this method, the metal oxide and the metal element in at least one kind of the plurality kinds of catalytic units are determined as a combination which can synergically enhance the catalytic function.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to catalysts, and more particularly to integrated catalysts.

[0002]

2. Description of the Related Art Exhaust gas emitted from waste incineration facilities and automobiles contains many substances including carbon monoxide, aldehydes, sulfides, hydrocarbons, nitrogen compounds and organic chlorine compounds. Contains various types of harmful substances. For this reason, in waste incineration facilities and the like, attempts have been made to treat exhaust gas using a catalyst to reduce the concentration of harmful substances contained therein.

[0003] Incidentally, the catalyst usually shows a peculiar decomposition activity only for a specific kind of harmful substance, and does not show a universal decomposition activity for all kinds of harmful substances. Also, some of the harmful substances may even deactivate certain catalysts. For example, a catalyst in which platinum element is supported on soot has high oxidative decomposition activity for hydrocarbons in a high temperature range, but is easily poisoned and inactivated by carbon monoxide in a low temperature range. For this reason, when it is necessary to effectively treat exhaust gas containing many kinds of harmful substances, a method using a combination of many kinds of catalysts according to the kind of harmful substances, for example, using many kinds of existing catalysts A method of uniformly mixing and using is considered.

However, in the case where various types of catalysts are mixed, even if the catalysts are mixed uniformly, different types of catalysts are located far apart at the μm level. Since the decomposition of harmful substances by the catalyst is based on the reaction at the molecular level on the catalyst, multiple types of harmful substances can be effectively and simultaneously effective unless different types of catalysts are close to each other at the molecular level. It is difficult to disassemble.

An object of the present invention is to provide a catalyst which can simultaneously and effectively exert activities on a plurality of different types of substances.

[0006]

The integrated catalyst according to the present invention comprises a group of catalyst units including a large number of catalyst units of a plurality of types, and the catalyst units are assembled at a nanometer level to form a group of catalyst units. .

Here, the plurality of types of catalyst units are, for example,
Each has its own catalytic function and at least one catalytic unit is selected to be able to complement at least one catalytic function of the other catalytic units. Further, each of the plurality of types of catalyst units is, for example,
It consists of a combination of a metal oxide and a metal element. In this case, the metal oxide and the metal element of at least one of the plurality of types of catalyst units are set to a combination capable of synergistically enhancing the catalytic function.

The above-mentioned catalyst unit group is disposed, for example, on a carrier. In this case, the carrier is, for example, one selected from activated carbon and activated carbon fiber.

One embodiment of the integrated catalyst according to the present invention comprises a first catalyst unit in which a gold element is supported on diiron trioxide, a second catalyst unit in which a platinum element is supported on tin dioxide, and an iridium element. A catalyst unit group comprising a large number of third catalyst units each supported on lanthanum oxide; a first catalyst component;
The second catalyst component and the third catalyst component assemble at a nanometer level to form a catalyst unit group. In the integrated catalyst according to this embodiment, for example, the catalyst unit group is disposed on one type of carrier selected from activated carbon and activated carbon fiber.

The method for producing an integrated catalyst according to the present invention is intended to produce an integrated catalyst in which a plurality of types of catalyst units in which a specific metal element is combined with a metal oxide are assembled at a nanometer level. A first step of preparing a metal oxide group including a plurality of types of metal oxides integrated at the nanometer level, and corresponding to each of the metal oxides included in the metal oxide group. A second step of selectively supporting the metal element to be carried out.

In the second step, for example, utilizing only a difference in isoelectric point between a plurality of types of metal oxides, only one type of metal oxide in the group of metal oxides is used. A step of selectively adhering ions of the metal element to be performed, and a step of converting the ions of the metal element to a metal element. It repeats every time.

In the second step, the step of converting the metal element ion into the metal element includes, for example, a step of inducing the metal element ion to a metal element hydroxide and a step of converting the metal hydroxide to a metal element hydroxide. Converting to an element.

The above-described method for producing an integrated catalyst according to the present invention comprises, for example, a metal oxide precursor that can be converted to a metal oxide and a metal element that can be converted to a metal element corresponding to the metal oxide. The method may further include a third step including a step of simultaneously depositing the precursor and a step of converting the metal oxide precursor and the metal element precursor into a metal oxide and a metal element, respectively.

In this case, the third step may be repeated a plurality of times. In addition, the third step may be performed at least once while the multi-step step in the second step is repeated.

Another method for producing an integrated catalyst according to the present invention relates to the above-described embodiment of the integrated catalyst according to the present invention, that is, the first method in which a gold element is supported on diiron trioxide.
A first catalyst component, a second catalyst unit including a large number of catalyst units, a second catalyst unit in which platinum element is supported on tin dioxide, and a catalyst unit group including a large number of third catalyst units in which iridium element is supported on lanthanum oxide; A method for producing an integrated catalyst in which a component and a third catalyst component are assembled at a nanometer level to form a group of catalyst units. This manufacturing method includes the following steps.

A step of preparing an aqueous solution containing diiron trioxide and tin dioxide accumulated at the nanometer level. ◎ The platinum compound is dissolved in the aqueous solution and the pH of the aqueous solution is set to be more alkaline than the isoelectric point of tin dioxide and more acidic than the isoelectric point of diiron trioxide, and the platinum cation from the platinum compound is dissolved. Selectively adheres only to tin dioxide,
Inducing platinum hydroxide from platinum cations by further adjusting the pH of the aqueous solution to an alkaline side within a range not exceeding the isoelectric point of ferric trioxide. ◎ Process of heat-treating platinum hydroxide to convert it to platinum element. ◎ Dissolve the gold compound in the aqueous solution and set the pH of the aqueous solution between the isoelectric point of tin dioxide and the isoelectric point of diiron trioxide,
A step of selectively adhering a gold anion from a gold compound only to diiron trioxide and further adjusting the pH of the aqueous solution to an alkaline side to induce gold hydroxide from the gold anion. ◎ Step of heat-treating gold hydroxide to convert it to gold element. ◎ After dissolving the lanthanum salt and the iridium salt in the aqueous solution,
Adjusting the pH of the aqueous solution to generate lanthanum hydroxide and iridium hydroxide in the aqueous solution. A step of heat-treating lanthanum hydroxide and iridium hydroxide to convert them into lanthanum oxide and iridium, respectively;

[0017]

DETAILED DESCRIPTION OF THE INVENTION The integrated catalyst of the present invention contains a large number of catalyst units. In the present invention, the catalyst unit is
A unit that can exhibit its own catalytic function by itself. For example, a catalyst element in the present invention includes a metal element, a metal oxide, and a combination of a metal element and a metal oxide (hereinafter, may be referred to as a “composite catalyst”).

Here, the metal element is a known metal element which is known to be capable of decomposing at least one of various harmful substances contained in various exhaust gases, for example. Specifically, gold, platinum, iridium, ruthenium, rhodium, palladium and silver can be exemplified.

In addition, the metal oxide carries the above-mentioned metal element.
Exhibits the same catalytic function as metal elements as a body or co-catalyst
It is a known thing that is known to be able to
Is diiron trioxide (Fe_TwoO_Three), Tin dioxide (SnO)_Two)
And lanthanum oxide (La_TwoO _Three) Can be illustrated
You. Other metal oxides include aluminum,
Silicon, magnesium, titanium, vanadium, manga
, Cobalt, nickel, copper, zinc, zirconium,
Of, molybdenum, tungsten, cerium, praseo
An oxide of a metal element such as gym can be given.

Further, a combination of a metal element and a metal oxide, that is, a composite catalyst is, for example, a combination of one of the above metal elements and one of the above metal oxides. is there. More specifically, a material in which diiron trioxide carries a gold element, a material in which tin dioxide carries platinum, and a material in which lanthanum oxide carries iridium can be exemplified.

The catalyst unit of the composite catalyst is composed of the metal element and the metal oxide such that the metal element and the metal oxide constituting the catalyst unit share functions and have a synergistic effect that can enhance the required catalyst functions. Are preferably combined.
For example, a catalyst unit in which platinum element is supported on tin dioxide, which can easily take in gas phase oxygen in the oxidative decomposition of hydrocarbons, can be oxidized by hydrocarbons that can be achieved by tin dioxide alone or platinum element alone. Compared with the activity, when both are combined, the oxidative decomposition activity increases synergistically. Further, the catalyst units is supported iridium element having a decomposition activity for amines lanthanum oxide having an affinity for NO _x is may exhibit degradation activity against Likewise amines in lanthanum oxide alone or iridium alone, both Are combined, the decomposition activity increases synergistically.

The integrated catalyst of the present invention contains a plurality of types of the above catalyst units. The combination of the types of the catalyst units is not particularly limited, for example, a combination of a plurality of types of metal elements, a combination of a plurality of types of metal oxides, a combination of a plurality of types of composite catalysts, and a metal element,
It is a combination of two or more of a metal oxide and a composite catalyst. In the present invention, since the required catalytic function can be exhibited most effectively, each of a plurality of types of catalyst units is a composite catalyst, that is, a combination of a metal oxide and a metal element. Is preferred.

The combination of catalyst units from the functional viewpoint of the catalyst can be appropriately set according to the use of the integrated catalyst of the present invention, in other words, the catalyst function required for the integrated catalyst of the present invention. Although not limited, usually
Each catalyst unit has a unique catalyst function different from other catalyst units, and at least one catalyst unit is set so as to complement the catalyst function of at least one catalyst unit of the other catalyst units. Is preferred. Incidentally, the term "complementary to the catalytic function" as used herein means that one catalytic unit maintains or promotes the catalytic activity of another catalytic unit.

For example, a catalyst unit having platinum element supported on tin dioxide, which exhibits oxidative decomposition activity for hydrocarbons,
And NO _x in the case of using at least one of the catalyst units is supported iridium element indicating the degradation activity against amines lanthanum oxide exhibits an affinity, these catalysts units to decompose hydrocarbons or amines Since it is easily poisoned by carbon monoxide that is sometimes generated and loses its catalytic activity, in order to maintain the catalytic activity of those catalyst units, diiron trioxide, which exhibits a decomposition activity for carbon monoxide, is made of gold. It is preferable to combine catalyst units carrying elements.

The integrated catalyst of the present invention comprises a group of catalyst units including a large number of the above-described plural types of catalyst units. Here, the catalyst unit group is not simply a mixture of a large number of plural types of catalyst units, but a sub-nanometer level in which many of the plural types of catalyst units are several times as large as atoms or molecules. It is gathered and integrated. FIG. 1 shows a conceptual diagram of one embodiment of such an integrated catalyst of the present invention.
In the figure, the integrated catalyst 1 has three types of catalyst units a and b.
And a catalyst unit group U containing a large number of each of
The catalyst units a, b and c are randomly stacked in layers. FIG. 2 shows a conceptual diagram of another embodiment of the integrated catalyst. In the figure, the integrated catalyst 2 is composed of a catalyst unit group U including a large number of each of three types of catalyst units a, b and c, similarly to the embodiment shown in FIG. They are randomly arranged in layers.

The integrated catalysts 1 and 2 of the above-described embodiments are
May be arranged on the carrier S. The carrier used here is not particularly limited as long as it can support the catalyst unit group U, and examples thereof include activated carbon, activated carbon fiber, alumina, and silica. Among them, in the present invention, it is preferable to use activated carbon or activated carbon fiber as a carrier. Activated carbon and activated carbon fiber have a large number of pores reaching a diameter of several tens of angstroms, and as a result, the specific surface area is much larger than that of other carriers. Many can be supported. In addition, due to its unique pore structure, fine-particle harmful substances and harmful substances having a large Van der Waals radius can be effectively adsorbed in the pores. It can also be effectively decomposed by the group of catalyst units supported in the pores. Therefore, when activated carbon or activated carbon fiber is used as the carrier, the effect of the integrated catalyst of the present invention can be further enhanced.

Preferred as the integrated catalyst of the present invention is a composite catalyst in which each of a plurality of types of catalyst units comprises a combination of a metal oxide and a metal element, and at least one of such catalyst units. One is selected such that it can complement the catalytic function of at least one of the other catalytic units. In this case, it is particularly preferable that at least one of the catalyst units is set to a combination in which the metal oxide and the metal element can synergistically enhance the catalytic function as described above.

As an example of such an integrated catalyst, a first catalyst unit in which a gold element is supported on diiron trioxide, a second catalyst unit in which a platinum element is supported on tin dioxide, and iridium element are lanthanum oxide One example includes a large number of three types of catalyst units of a third catalyst unit supported thereon, and these catalyst units are assembled at a nanometer level to form a catalyst unit group. The catalyst unit group may be arranged on a carrier made of activated carbon or activated carbon fiber.

In such an integrated catalyst, the first catalyst component exhibits excellent low-temperature oxidative decomposition activity against carbon monoxide and aldehydes. In particular, it exhibits excellent oxidative decomposition activity against carbon monoxide even at -70 ° C. In addition, the second catalyst component exhibits excellent oxidative decomposition activity against hydrocarbons and the like in a high temperature range. Furthermore, the third catalyst component exhibits excellent decomposition activity for amines. Therefore, when this integrated catalyst is used as a catalyst for treating an exhaust gas containing an organic chlorine compound such as carbon monoxide, aldehydes, hydrocarbons, amines, mercaptans, and dioxin, the integrated catalyst is contained in the exhaust gas. The concentration of these contained harmful substances can be simultaneously and effectively reduced at a relatively low temperature, and their functions can be maintained for a long time.

In particular, in the integrated catalyst, the first catalyst unit can perform a complementary function of the second catalyst unit and the third catalyst unit. That is, the second catalyst unit and the third catalyst unit are:
In some cases, they are poisoned by carbon monoxide generated by themselves when hydrocarbons and amines are decomposed and carbon monoxide contained in exhaust gas, and their activity may be significantly reduced. Since the activity can be decomposed by one catalyst unit, the activities of the second and third catalyst units can be maintained.

That is, this integrated catalyst is different from a catalyst in which the first catalyst unit, the second catalyst unit and the third catalyst unit are simply mixed uniformly, and these catalyst units are aggregated at a nanometer level. Because they are integrated (ie, each catalyst unit is assembled in close proximity at the nanometer level), the carbon monoxide produced by the reaction at the molecular level in the second catalyst unit and the third catalyst unit is converted into those catalysts. It can be rapidly decomposed by the first catalyst component located close to the unit at the nanometer level.

As a result, the integrated catalyst can exhibit the required catalytic function effectively and continuously for a long period of time.
Since such an integrated catalyst of the present invention can exhibit the above-described functions, for example, a catalyst for treating exhaust gas discharged from a refuse incineration plant or various industrial plants, a catalyst for an air purifier, and a fuel It can be used as a battery catalyst or the like.

The integrated catalyst of the present invention can be produced by simultaneously depositing various metal elements and metal oxides in an aqueous solution by a known method such as a coprecipitation method. However, among the integrated catalysts, when a plurality of types of catalyst units in which a metal element and a metal oxide are combined are aggregated at a nanometer level, a specific metal element and a specific metal oxide are paired. Therefore, it is difficult to produce by a common coprecipitation method. Therefore, a method for producing such an integrated catalyst will be described below.

Here, as an example, an integrated catalyst comprising a group of catalyst units including a large number of catalyst units in which a gold element is supported on diiron trioxide and a large number of catalyst units in which a platinum element is supported on tin dioxide, The manufacturing method will be described for each process.

First Step In this step, a group of metal oxides in which a plurality of types of metal oxides, that is, diiron trioxide and tin dioxide are integrated at a nanometer level is prepared. Here, first, an aqueous solution containing an iron salt and a tin salt (for example, both nitrates) is prepared,
Iron hydroxide and tin hydroxide are prepared by gradually adjusting the pH of this aqueous solution to the alkaline side. here,
As a method for adjusting the pH of the aqueous solution to the alkaline side, for example, urea is previously dissolved in the aqueous solution,
A method of heating this aqueous solution to about 70 ° C., a method of gradually dropping an aqueous sodium carbonate solution or an aqueous sodium hydroxide solution into the aqueous solution, and the like can be adopted.

In the case of the method described above, when the aqueous solution is heated, urea is slowly decomposed to generate NH ₄ ⁺ ions and OH ^- ions. As a result, the pH of the aqueous solution gradually changes to an alkaline side, and when the pH value becomes more alkaline than a certain value, water-insoluble iron hydroxide and tin hydroxide precipitate in the aqueous solution while gathering at a nanometer level. And precipitate in aqueous solution. When the obtained metal hydroxide group is heat-treated in an oxygen-containing atmosphere, the metal hydroxide group is converted into a target metal oxide group, that is, a metal oxide group containing diiron trioxide and tin dioxide. Is done.

On the other hand, in the case of the above method, an aqueous solution of sodium carbonate or an aqueous solution of sodium hydroxide is gradually dropped while stirring the aqueous solution containing the metal salt, ie, the iron salt and the tin salt. As a result, the pH of the aqueous solution gradually changes to an alkaline side, and when the pH value becomes more alkaline than a certain value, water-insoluble iron hydroxide and tin hydroxide precipitate in the aqueous solution while gathering at a nanometer level. And precipitate in aqueous solution. When the obtained metal hydroxide group is heat-treated in an oxygen-containing atmosphere, the metal hydroxide group is converted into a target metal oxide group, that is, a metal oxide group containing diiron trioxide and tin dioxide. You.

In this step, as described above, a plurality of metal salts may be simultaneously added to the aqueous solution to generate a plurality of metal oxides corresponding thereto, or one metal salt may be added. The metal oxides may be added one by one and the corresponding metal oxides may be sequentially generated one by one.

In the case of producing an integrated catalyst in which the catalyst unit group is arranged on a carrier, in this step, the carrier is previously arranged in an aqueous solution. In this case, the above-mentioned metal hydroxide group precipitates on the carrier, so that the metal oxide group can be generated (supported) on the carrier.

Second Step In this step, each of the metal oxides contained in the group of metal oxides obtained in the first step, that is, each of diiron trioxide and tin dioxide is treated with a corresponding metal element. ,
That is, the gold element and the platinum element are selectively carried.

Here, utilizing the difference in isoelectric point between diiron trioxide and tin dioxide, the corresponding metal element is selectively carried on both. FIG. 3 shows the relationship between the ion adsorption density and the pH in an aqueous solution of diiron trioxide and tin dioxide. As shown in the figure, the isoelectric point (pH) of tin dioxide is 4.5, and the isoelectric point of diiron trioxide is 8.0. Therefore, when the pH of the aqueous solution is less than 4.5, both the surfaces of tin dioxide and diiron trioxide are positively charged. When the pH of the aqueous solution is in the range of 4.5 to 8.0, the surface of tin dioxide is negatively charged and the surface of diiron trioxide is positively charged.

In this step, by utilizing the above-mentioned difference in the isoelectric points of diiron trioxide and tin dioxide, the corresponding metal element can be selectively carried on these metal oxides. it can. Specifically, first, a platinum compound (for example, a platinum salt, more specifically, for example, platinum chloride) is added to an aqueous solution containing diiron trioxide and tin dioxide, and the pH of the aqueous solution is 4.5 or more. In addition, it is set to be more acidic than the isoelectric point of diiron trioxide. As a result, the cationic platinum ion (Pt ⁴⁺ ) generated in the aqueous solution is attracted to the surface of tin dioxide having a negative charge at the pH, and is converted to diiron trioxide having a positive charge. You will be repelled.

In this state, when the pH of the aqueous solution is further set to the alkaline side, the platinum ion becomes platinum hydroxide (Pt (O
H) ₄ · 2H ₂ O), and the selectively deposited only on the tin dioxide. Thereafter, when the metal oxide group is taken out from the aqueous solution and heat-treated, platinum hydroxide is converted to platinum element, and a metal oxide group containing tin dioxide and diiron trioxide carrying platinum element is obtained.

Next, an aqueous solution of the metal oxide group is prepared again, and a gold compound (for example, an acid containing a gold element, more specifically, for example, chloroauric acid) is added thereto. When the pH of the aqueous solution is set to 4.5 or more and on the acidic side with respect to the isoelectric point of diiron trioxide, the anionic gold ion (for example, AuCl ₄ ⁻ ) generated in the aqueous solution is adjusted to the pH. In the area, the surface will be attracted to the positively charged diiron trioxide and will repel the negatively charged tin dioxide. In this state, when the pH of the aqueous solution is further set to the alkaline side, the gold ion becomes gold hydroxide (Au (O
H) ₃ ) and selectively precipitate only on diiron trioxide. Thereafter, when the metal oxide group is taken out of the aqueous solution and heat-treated, the gold hydroxide is converted to a gold element. As a result,
A catalyst unit group including a large number of catalyst units made of tin dioxide carrying platinum element and catalyst units made of diiron trioxide carrying gold element, that is, a target integrated catalyst is obtained. When the metal oxide group is formed on the carrier in the first step, the integrated catalyst is formed on the carrier.

Third step In addition to a catalyst unit composed of tin dioxide carrying platinum element and a catalyst unit composed of diiron trioxide carrying gold element,
For example, when manufacturing an integrated catalyst comprising a catalyst unit group further including a catalyst unit comprising lanthanum oxide supporting an iridium element, the integrated catalyst obtained through the first step and the second step as described above For this, a third step described below is further applied.

In this step, first, a metal oxide precursor which can be converted to lanthanum oxide and a metal element precursor which can be converted to iridium element are simultaneously applied to the integrated catalyst obtained in the second step. Precipitate. In addition, the metal oxide precursor and the metal element precursor mentioned here are, for example, lanthanum hydroxide and iridium hydroxide, respectively.

Here, usually, a metal salt (a lanthanum salt in this example, more specifically, for example, lanthanum nitrate) for forming a metal oxide precursor and a metal element precursor for forming a metal element precursor are usually used. An aqueous solution containing a metal salt (in this case, an iridium salt, more specifically, for example, iridium chloride) is prepared, and the integrated catalyst obtained in the second step is added to the aqueous solution. Then, the pH of the aqueous solution is gradually adjusted to an alkaline side, and lanthanum hydroxide (metal oxide precursor) and iridium hydroxide (metal element precursor) are simultaneously precipitated. At this time, the lanthanum hydroxide and the iridium hydroxide aggregate and precipitate together at the nanometer level, and simultaneously precipitate at the nanometer level on the integrated catalyst obtained in the second step.

As a method for adjusting the pH of the aqueous solution, a method similar to the method that can be adopted in the first step described above, that is, a method in which urea is added to the aqueous solution and heated to about 70 ° C. And a method in which an aqueous solution of sodium carbonate or an aqueous solution of sodium hydroxide is gradually added dropwise to the aqueous solution.

Next, the integrated catalyst in which lanthanum hydroxide and iridium hydroxide are additionally added is taken out of the aqueous solution, and is heat-treated in the air. As a result, the lanthanum hydroxide and the iridium hydroxide are simultaneously converted into the lanthanum oxide and the iridium element, respectively, and a new catalyst unit composed of the lanthanum oxide supporting the iridium element is generated. Thus, a catalyst unit comprising three types of catalyst units, a catalyst unit comprising tin dioxide carrying a platinum element, a catalyst unit comprising diiron trioxide carrying a gold element, and a catalyst unit comprising lanthanum oxide carrying an iridium element An integrated catalyst consisting of groups is obtained.

In the above-mentioned heat treatment step at the final stage, iridium hydroxide may be converted to iridium oxide depending on the conditions at that time. In this case, it is necessary to heat-treat it in a reducing atmosphere. , Can be converted to iridium element.

The above-described production method according to the present invention comprises an integrated catalyst other than the integrated catalyst according to the above-described example, that is, a plurality of types of catalyst units in which a metal element is supported on a metal oxide. The present invention can be applied to the case of manufacturing other integrated catalysts. In this case, a metal oxide group containing three or more types of metal oxides is formed in the first step described above,
On the other hand, the second step may be repeated three or more times depending on the type of the catalyst unit. Also, depending on the type of catalyst unit,
The above third step may be repeated two or more times. Further, in the above-described manufacturing method, it is not always necessary to perform the third step after completing the first step and the second step, and to perform the first and second steps after performing the third step. The step may be performed, or the third step may be appropriately performed once or twice while repeatedly applying the second step to the metal oxides included in the metal oxide group obtained in the first step. It may be inserted more than once.

[0052]

EXAMPLE 1 500 ml of water was added to an eggplant-shaped flask, and 10 g of water was added thereto.
Coal tar pitch based activated carbon fiber (average fiber diameter = 1
4.0 μm, BET specific surface area = 1,920 m ² / g, average pore diameter = 19.01 Å). At this time, in order to allow water to penetrate into the pores of the activated carbon fiber,
The inside of the eggplant-shaped flask was subjected to vacuum degassing for about 10 minutes.

Next, the activated carbon fibers in the eggplant-shaped flask were transferred together with water to a cylindrical bottle with a lid, to which 0.006 mol of Fe (NO ₃ ) ₃ .9H ₂ O and 0.006 mol of SnC were added.
Add ₄ and 0.036 mol of urea and dissolve, add 50
0 ml of an aqueous solution was obtained. Then, this aqueous solution was subjected to a heat treatment for 5 hours while being stirred in a water bath at 80 ° C.
At this time, urea in the aqueous solution was hydrolyzed to generate OH ^- ions, and the pH of the aqueous solution gradually shifted to the alkaline side. As a result, iron hydroxide (Fe (OH) ₃ ) and tin hydroxide (Sn (OH) ₄ ) were precipitated and precipitated on the activated carbon fibers in the aqueous solution.

The activated carbon fiber was taken out of the aqueous solution, sufficiently washed with water while being suctioned by an aspirator, and then dried under vacuum for about 10 hours. This activated carbon fiber is filled in a gas flow type quartz tube, and a mixed gas containing 2% by volume of oxygen and 98% by volume of nitrogen is flowed through the quartz tube at a flow rate of 250 ml / min per approximately 1 g of the activated carbon fiber. The activated carbon fibers were baked at 300 ° C. for 3 hours. As a result, iron hydroxide and tin hydroxide were converted into oxides, and activated carbon fibers carrying diiron trioxide and tin dioxide were obtained.

Next, 10 g of activated carbon fibers carrying diiron trioxide and tin dioxide were placed in 500 ml of water in an eggplant-shaped flask.
1 and degassed as described above. Thereafter, the activated carbon fibers were transferred together with water to a cylindrical bottle with a lid, and 0.0003 mol of PtCl ₄ was added thereto to prepare a 500 ml aqueous solution. The pH of this aqueous solution was 1.8.

Stir until the pH of the aqueous solution reaches 6.0.
A 5% aqueous solution of sodium carbonate is slowly added dropwise.
The aqueous solution was aged for 2 hours while maintaining the pH of the solution. This
If the pH of the aqueous solution exceeds the isoelectric point of tin dioxide,
In other words, when the pH exceeds 4.5, platinum ions (Pt)
⁴⁺) Selectively on negatively charged tin dioxide surfaces only
When the pH shifts to 6.0, the platinum ion becomes hydroxyl.
Platinum oxide (Pt (OH) _Four・ 2H_TwoO)
And precipitated only on the surface of the dust.

The activated carbon fiber treated as described above was taken out of the aqueous solution, washed sufficiently with water while sucking it with an aspirator, and dried in vacuum for about 10 hours. This activated carbon fiber is filled in a gas flow type quartz tube, and a mixed gas containing 2% by volume of oxygen and 98% by volume of nitrogen is flowed through the quartz tube at a flow rate of 250 ml / min per approximately 1 g of the activated carbon fiber. The activated carbon fibers were baked at 300 ° C. for 3 hours. Subsequently, hydrogen gas was introduced into the quartz tube by about 1% of activated carbon fiber.
The activated carbon fibers were reduced at 200 ° C. for 3 hours while flowing at a flow rate of 100 ml / min. As a result, an activated carbon fiber carrying a catalyst unit composed of tin dioxide carrying platinum element and diiron trioxide was obtained.

Next, 10 g of activated carbon fibers carrying tin dioxide and a catalyst unit composed of tin dioxide carrying platinum element were immersed in 500 ml of water in an eggplant-shaped flask, and degassed in the same manner as described above. . Thereafter, the activated carbon fibers was transferred to a capped cylindrical bottle with water, to prepare an aqueous solution of 500ml and added with 0.0003 moles of HAuCl ₄ · 4H ₂ O. The pH of this aqueous solution was 2.8.

A 5% aqueous sodium carbonate solution was slowly added dropwise with stirring until the pH of the aqueous solution reached 7.0, and the aqueous solution was aged for 5 hours while maintaining this pH. In this process, when the pH of the aqueous solution becomes equal to or higher than the isoelectric point of tin dioxide, that is, 4.5 or higher, gold ions (AuC
l ^4- ) selectively migrates only to the surface of positively charged diiron trioxide, and when the pH reaches 7.0, the gold ion changes to gold hydroxide (Au (OH) ₃ ). As a result, it was deposited only on the surface of diiron trioxide and precipitated.

The activated carbon fiber treated as described above was taken out of the aqueous solution, washed thoroughly with water while sucking it with an aspirator, and dried in vacuum for about 10 hours. This activated carbon fiber is filled in a gas flow type quartz tube, and a mixed gas containing 2% by volume of oxygen and 98% by volume of nitrogen is flowed through the quartz tube at a flow rate of 250 ml / min per approximately 1 g of the activated carbon fiber. The activated carbon fibers were baked at 300 ° C. for 3 hours. As a result, an activated carbon fiber carrying two catalyst units, that is, a catalyst unit consisting of tin dioxide carrying platinum element and a catalyst unit consisting of diiron trioxide carrying gold element, that is, an integrated catalyst was obtained. The composition and physical properties of the obtained integrated catalyst are as shown in Table 1.

[0061]Example 2 10 g of the integrated catalyst obtained in Example 1 was used in an eggplant-shaped flask.
Immersed in 500 ml of water in the same manner as in Example 1.
After degassing, the integrated catalyst and water
Transferred to mold bottle. 0.006 mol of La (NO_Three)_Three
・ 6H_TwoO, 0.0003 mol IrCl_ThreeAnd 0.0
19 moles of urea were added to make a 500 ml aqueous solution
Was. Then, put this aqueous solution in a water bath at 80 ° C.
Heat treatment was performed for 5 hours while stirring. At this time,
Urea hydrolyzes to OH^-Ions are generated and the p
H gradually shifted to the alkaline side. As a result, the aqueous solution
The activated carbon fibers that constitute the integrated catalyst in the
Rhidium (Ir (OH) _Three) And lanthanum hydroxide (La
(OH)_Three) Was precipitated.

The integrated catalyst treated as described above was taken out of the aqueous solution, sufficiently washed with water while being suctioned by an aspirator, and dried in vacuum for about 10 hours. The integrated catalyst was filled in a gas flow type quartz tube, and the integrated catalyst was calcined at 300 ° C. for 3 hours while flowing air through the quartz tube at a flow rate of 250 ml / min for about 1 g of the integrated catalyst.
Subsequently, while flowing hydrogen gas through the quartz tube at a flow rate of 100 ml / min with respect to about 1 g of the integrated catalyst, the integrated catalyst was supplied for 2 hours.
Reduction treatment was performed at 00 ° C. for 3 hours. As a result, in addition to the catalyst unit consisting of tin dioxide carrying platinum element and the catalyst unit consisting of diiron trioxide carrying gold element, the catalyst unit consisting of lanthanum oxide carrying iridium element is accumulated on the activated carbon fiber. The obtained integrated catalyst was obtained. The composition and physical properties of the obtained integrated catalyst are as shown in Table 1.

[0063] Example 3 500 ml of 0.6 molar aqueous lidded cylindrical bottle charged with the _{Fe (NO 3) 3 · 9H} 2 O, 0.6 mol of SnCl ₄ and 3.6 moles of urea added And dissolved to obtain an aqueous solution.
Then, this aqueous solution was subjected to a heat treatment for 5 hours while being stirred in a water bath at 80 ° C. At this time, urea in the aqueous solution was hydrolyzed to generate OH ^- ions, and the pH of the aqueous solution gradually shifted to the alkaline side. As a result, iron hydroxide (Fe (OH) ₃ ) and tin hydroxide (Sn (OH) ₄ ) were precipitated and precipitated on the activated carbon fibers in the aqueous solution.

This aqueous solution was filtered to collect a precipitate, which was thoroughly washed with water while suctioning with an aspirator, and then dried under vacuum for about 10 hours. Thereafter, the precipitate was filled in a gas flow type quartz tube, and air was poured into the quartz tube for about 1 g of the precipitate.
The precipitate was calcined at 300 ° C. for 3 hours while flowing at a flow rate of 50 ml / min. As a result, a metal oxide group consisting of diiron trioxide and tin dioxide was obtained.

Next, 10 g of the metal oxide group was immersed in 500 ml of water in an eggplant-shaped flask, and degassed in the same manner as described above. Thereafter, the metal oxide group was transferred together with water to a cylindrical bottle with a lid, to which 0.03 mol of PtCl ₄ was added to form a mixture.
A 00 ml aqueous solution was prepared. The pH of this aqueous solution was 1.
It was 8.

Stir until the pH of the aqueous solution reaches 6.0.
A 5% aqueous solution of sodium carbonate is slowly added dropwise.
The aqueous solution was aged for 5 hours while maintaining the pH of the solution. This
If the pH of the aqueous solution exceeds the isoelectric point of tin dioxide,
In other words, when the pH exceeds 4.5, platinum ions (Pt)
⁴⁺) Selectively on negatively charged tin dioxide surfaces only
When the pH shifts to 6.0, the platinum ion becomes hydroxyl.
Platinum oxide (Pt (OH) _Four) Change to tin dioxide surface
And precipitated.

The metal oxide group treated as described above was taken out of the aqueous solution, washed thoroughly with water while suctioning with an aspirator, and then dried in vacuum for about 10 hours. The metal oxide group was filled in a gas flow type quartz tube, and the metal oxide group was calcined at 300 ° C. for 3 hours while flowing air through the quartz tube at a flow rate of 250 ml / min for about 1 g of the metal oxide group. . Subsequently, the metal oxide group was reduced at 200 ° C. for 3 hours while flowing hydrogen gas through the quartz tube at a flow rate of 100 ml / min for about 1 g of the metal oxide group. As a result,
A composite of a catalyst unit composed of tin dioxide carrying platinum element and diiron trioxide was obtained.

Next, 10 g of the composite was immersed in 500 ml of water in an eggplant-shaped flask and degassed as described above. Thereafter, the composite was transferred to a capped cylindrical bottle with water added thereto 0.03 moles of HAuCl ₄ · 4H ₂ O 500
A ml aqueous solution was prepared. The pH of this aqueous solution was 2.8.

A 5% aqueous solution of sodium carbonate was slowly added dropwise with stirring until the pH of the aqueous solution reached 7.0, and the aqueous solution was aged for 5 hours while maintaining this pH. In this process, when the pH of the aqueous solution becomes equal to or higher than the isoelectric point of tin dioxide, that is, 4.5 or higher, gold ions (AuC
l ^4- ) selectively migrates only to the surface of positively charged diiron trioxide, and when the pH reaches 7.0, the gold ion changes to gold hydroxide (Au (OH) ₃ ). As a result, it was deposited only on the surface of diiron trioxide and precipitated.

The composite treated as described above was taken out of the aqueous solution, filtered, washed sufficiently with suction by an aspirator, and dried in vacuum for about 10 hours.
The composite was filled in a gas flow type quartz tube, and the composite was calcined at 300 ° C. for 3 hours while flowing air through the quartz tube at a flow rate of 250 ml / min for about 1 g of the composite. As a result, a catalyst unit composed of tin dioxide carrying a platinum element and a catalyst unit composed of diiron trioxide carrying a gold element, 2
An integrated catalyst consisting of two catalyst units was obtained. The composition and physical properties of the obtained integrated catalyst are as shown in Table 1.

Comparative Example 1 Catalyst component 1, catalyst component 2 and catalyst component 3 obtained as described below were uniformly mixed at a ratio of 1: 1: 1 to obtain a mixed catalyst. The composition and physical properties of the obtained mixed catalyst are as shown in Table 1.

(Catalyst component 1) 500 m in an eggplant type flask
1 g of water was added thereto, and 10 g of coal tar pitch-based activated carbon fiber (average fiber diameter = 14.0 μm, BET specific surface area = 1,920 m ² / g, average pore diameter = 19.01 Å) was immersed in the water. At this time, in order to allow water to penetrate into the pores of the activated carbon fiber, about 10
Vacuum degassed for minutes.

Next, the activated carbon fiber in the eggplant-shaped flask were transferred to a capped cylindrical bottle with water, to which 0.006 mol of _{Fe (NO 3) 3 · 9H} 2 O, 0.0003 moles of HA
UCl ₄ .4H ₂ O and 0.057 mol of urea were added and dissolved to obtain 500 ml of an aqueous solution. Then, this aqueous solution was subjected to a heat treatment for 5 hours while being stirred in a water bath at 80 ° C. At this time, urea in the aqueous solution is hydrolyzed to O
H ^- ions were generated, and the pH of the aqueous solution gradually shifted to the alkaline side. As a result, the activated carbon fibers in the aqueous solution contain iron hydroxide (Fe (OH) ₃ ) and gold hydroxide (Au (O
H) ₃ ) precipitated and precipitated.

The activated carbon fibers were taken out of the aqueous solution, washed thoroughly with water while suctioning them with an aspirator, and then dried under vacuum for about 10 hours. This activated carbon fiber is filled in a gas flow type quartz tube, and a mixed gas containing 2% by volume of oxygen and 98% by volume of nitrogen is flowed through the quartz tube at a flow rate of 250 ml / min per approximately 1 g of the activated carbon fiber. The activated carbon fibers were baked at 300 ° C. for 3 hours. Thus, an activated carbon fiber (catalyst component 1) supporting the gold element and diiron trioxide was obtained.

(Catalyst component 2) 500 m in an eggplant type flask
1 g of water was added thereto, and 10 g of coal tar pitch-based activated carbon fiber (average fiber diameter = 14.0 μm, BET specific surface area = 1,920 m ² / g, average pore diameter = 19.01 Å) was immersed in the water. At this time, in order to allow water to penetrate into the pores of the activated carbon fiber, about 10
Vacuum degassed for minutes.

Next, the activated carbon fibers in the eggplant-shaped flask were transferred together with water to a cylindrical bottle with a lid, into which 0.006 mol of SnCl ₄ , 0.0003 mol of PtCl _4, and 0.03 mol of PtCl ₄ were added.
057 mol of urea was added and dissolved to obtain 500 ml of an aqueous solution. Then, this aqueous solution was subjected to a heat treatment for 5 hours while being stirred in a water bath at 80 ° C. Thereafter, the same operation as in the case of the catalyst component 1 was performed, whereby an activated carbon fiber carrying the platinum element and tin dioxide (catalyst component 2) was obtained.

(Catalyst component 3) 500 m in an eggplant type flask
1 g of water was added thereto, and 10 g of coal tar pitch-based activated carbon fiber (average fiber diameter = 14.0 μm, BET specific surface area = 1,920 m ² / g, average pore diameter = 19.01 Å) was immersed in the water. At this time, in order to allow water to penetrate into the pores of the activated carbon fiber, about 10
Vacuum degassed for minutes.

Next, the activated carbon fibers in the eggplant-shaped flask were transferred together with water to a cylindrical bottle with a lid, into which 0.006 mol of La (NO ₃ ) ₃ .6H ₂ O and 0.0003 mol of Ir were added.
Cl ₄ and 0.057 mol of urea were added and dissolved.
00 ml of an aqueous solution was obtained. Then, the aqueous solution is heated to 80 ° C.
Was heated for 5 hours while stirring in a water bath. Hereinafter, when the same operation as in the case of the catalyst component 1 was performed,
An activated carbon fiber carrying the iridium element and lanthanum oxide (catalyst component 3) was obtained.

Comparative Example 2 Catalyst component 1 and catalyst component 2 obtained as described below were uniformly mixed at a ratio of 1: 1 to obtain a mixed catalyst. The composition and physical properties of the obtained mixed catalyst are as shown in Table 1.

(Catalyst component 1) 0.6 mol of Fe (NO ₃ ) ₃ .9H ₂ O, 0.03 mol of HAu were placed in a cylindrical bottle with a lid.
Cl ₄ , 3.6 moles of urea and water were added and dissolved.
00 ml of an aqueous solution was obtained. At this time, about 1
Vacuum deaeration treatment was performed for 0 minutes. This aqueous solution was heat-treated for 5 hours while stirring in a water bath at 80 ° C. At this time, urea in the aqueous solution was hydrolyzed to generate OH ^- ions, and the pH of the aqueous solution gradually shifted to the alkaline side. As a result, iron hydroxide (Fe (OH) ₃ ) and gold hydroxide (Au (OH) ₃ ) were precipitated and precipitated in the aqueous solution.

The precipitate was filtered out of the aqueous solution, washed thoroughly with water while suctioning with an aspirator, and dried in vacuum for about 10 hours. The sediment is filled in a gas flow type quartz tube, and air is introduced into the quartz tube for about 1 g of the sediment for 250 g.
The precipitate was calcined at 300 ° C. for 3 hours while flowing at a flow rate of ml / min. As a result, a catalyst (catalyst component 1) composed of diiron trioxide supporting a gold element was obtained.

(Catalyst component 2) 0.6 mol of SnCl ₄ , 0.03 mol of PtCl ₄ , 3.6 mol of urea and water were added to a cylindrical bottle with a lid and dissolved to obtain 500 ml of an aqueous solution. . Thereafter, the same operation as in the case of the catalyst component 1 was performed, whereby a catalyst (catalyst component 2) composed of tin dioxide carrying platinum element was obtained.

[0083]

[Table 1]

Evaluation The catalysts obtained in each of the examples and comparative examples were evaluated for carbon monoxide (1,000 ppm) and o-chlorophenol (1,4).
00 ppm, acetaldehyde 700 ppm, hydrazine 750 ppm, methylamine 450 ppm, methyl mercaptan 200 ppm, water 3.9% by volume and oxygen 1
The decomposition activity and the activity stability with respect to a nitrogen mixed gas containing 8.65% by volume were examined. Example 3 and Comparative Example 2
The catalyst obtained in 1 was mixed with quartz sand having an average particle size of 0.5 mm at a ratio of 1: 4 (catalyst: quartz sand) as a sample.

(Decomposition Activity Test) The decomposition activity of the catalyst was evaluated using a fixed bed flow reactor. Here, a catalyst sample of 2.0 g was placed in a stainless steel reaction tube having an inner diameter of 19 mm.
(14 ml), and both ends of the reaction tube were sealed with an appropriate amount of glass wool. Then, 20,000 is added to this reaction tube.
The above-mentioned nitrogen mixed gas was passed under the conditions of hr ^-1 and a temperature of 130 ° C.

The nitrogen mixed gas before and after passing through the reaction tube was analyzed by gas chromatography (trade name “H1880T” of Yanagimoto Seisakusho Co., Ltd.). At this time, o-
F for detection of chlorophenol, acetaldehyde, hydrazine, methylamine and methylmercaptan
An ID detector was used, and a TCD detector was used for detecting carbon monoxide.

The decomposition activity of the catalyst was evaluated by determining the decomposition rate of each component contained in the nitrogen mixed gas. Here, the decomposition rate is determined by measuring the peak area of each component in gas chromatography measured at the inlet side of the reaction tube 2 hours after starting to flow the nitrogen mixed gas into the reaction tube, and the outlet of the reaction tube at the same point. It was calculated based on the peak area of each component in gas chromatography measured on the side. Table 2 shows the results.

(Activity stability)
Over time, the change in the degradation rate was examined. The results are shown in FIGS.
Shown in 4 shows the catalyst of Example 1, and FIG. 5 shows the catalyst of Example 2.
6 shows the result of the catalyst of Example 3, FIG. 7 shows the result of the catalyst of Comparative Example 1, and FIG. 8 shows the result of the catalyst of Comparative Example 2.

[0089]

[Table 2]

[0090]

According to the integrated catalyst of the present invention, a plurality of types of catalyst units are assembled at a nanometer level.
Unlike those that simply mix multiple types of catalysts,
Activities for a plurality of different types of substances can be effectively exhibited simultaneously.

Further, according to the method for producing a catalyst according to the present invention, a plurality of types of catalyst units in which a metal element and a metal oxide are combined, which are capable of simultaneously exhibiting an activity on a plurality of different types of substances simultaneously and effectively. Can be realized at the nanometer level.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram of one embodiment of an integrated catalyst of the present invention.

FIG. 2 is a conceptual diagram of another embodiment of the integrated catalyst of the present invention.

FIG. 3 is a graph showing a relationship between ion adsorption density and pH in an aqueous solution of diiron trioxide and tin dioxide.

FIG. 4 is a graph showing the activity stability of the catalyst according to Example 1.

FIG. 5 is a graph showing the activity stability of the catalyst according to Example 2.

FIG. 6 is a graph showing the activity stability of the catalyst according to Example 3.

FIG. 7 is a graph showing the activity stability of the catalyst according to Comparative Example 1.

FIG. 8 is a graph showing the activity stability of the catalyst according to Comparative Example 2.

[Explanation of symbols]

 1, 2 Integrated catalyst a, b, c Catalyst unit U Catalyst unit group S Carrier

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Mitsutaka Okumura 1-8-31 Midorioka, Ikeda-shi, Osaka Inside the Industrial Technology Research Institute, Osaka Institute of Technology (72) Inventor Osamu Kajikawa Hiranocho, Chuo-ku, Osaka-shi, Osaka 1-2 1-2, Osaka Gas Co., Ltd. (72) Inventor Osamu Okada 4-1-2, Hirano-cho, Chuo-ku, Osaka City, Osaka Prefecture 72-inch Inside Osaka Gas Co., Ltd. (72) Keiichi Den, Chudo, Shimogyo-ku, Kyoto City, Kyoto Prefecture Inside the Kansai New Technology Research Center, 17 Teranicho Co., Ltd. (72) Inventor Yoshio Wang In the Kansai New Technology Research Center, 17 Nakado-Jinancho, Shimogyo-ku, Kyoto, Kyoto Prefecture F-term (reference) BC22A BC22B BC42A BC42B BC66A BC66B BC74A BC74B BC75A BC75B BD12B CA03 CA12 CA13 CA14 CA15 CA17 CA19 EA03X EB18X EB18Y EE06 EE09 FA02 FB08 FB13 FB16 FB17 FB18 FB19 FB20 FB30 FB77 FC09

Claims (15)

[Claims] An integrated catalyst comprising a catalyst unit group including a large number of catalyst units of a plurality of types, wherein the catalyst units are assembled at a nanometer level to form the catalyst unit group. 2. A plurality of types of said catalyst units each have a unique catalyst function, and at least one type of catalyst unit complements at least one type of catalyst function of other types of catalyst units. The integrated catalyst according to claim 1, which is selected as possible. 3. The integrated catalyst according to claim 1, wherein each of the plurality of types of catalyst units comprises a combination of a metal oxide and a metal element. 4. The combination of the metal oxide and the metal element of at least one of a plurality of types of the catalyst units is set so as to synergistically enhance the catalytic function.
An integrated catalyst according to claim 3. 5. The integrated catalyst according to claim 1, wherein said group of catalyst units is arranged on a carrier. 6. The integrated catalyst according to claim 5, wherein said carrier is one selected from activated carbon and activated carbon fibers. 7. A first catalyst unit in which a gold element is supported on diiron trioxide, a second catalyst unit in which a platinum element is supported on tin dioxide, and a third catalyst in which an iridium element is supported on lanthanum oxide An integrated catalyst comprising a catalyst unit group including a plurality of units, wherein the first catalyst component, the second catalyst component, and the third catalyst component are assembled at a nanometer level to form the catalyst unit group. 8. The catalyst unit group is disposed on one type of carrier selected from activated carbon and activated carbon fiber,
An integrated catalyst according to claim 7. 9. A method for producing an integrated catalyst in which a plurality of types of catalyst units in which a specific metal element is combined with a metal oxide is assembled at a nanometer level. A first step of preparing a metal oxide group containing a plurality of types of the metal oxides, and selecting the metal element corresponding to each of the metal oxides included in the metal oxide group A method for producing an integrated catalyst, the method comprising: 10. The method according to claim 1, wherein the second step uses only a difference in isoelectric point between a plurality of types of the metal oxides to apply only one type of the metal oxides in the group of the metal oxides. Selectively depositing ions of the corresponding metal element;
10. The integration according to claim 9, further comprising the step of: converting ions of the metal element into the metal element, wherein a multi-step process consisting of these steps is repeated for each type of the metal oxide included in the metal oxide group. Production method of the conversion catalyst. 11. The step of converting the ions of the metal element to the metal element includes the steps of: inducing the ions of the metal element to a hydroxide of the metal element; and converting the hydroxide to the metal element. 11. The method for producing an integrated catalyst according to claim 10, comprising the steps of: 12. A step of simultaneously depositing a metal oxide precursor convertible to the metal oxide and a metal element precursor convertible to the metal element corresponding to the metal oxide;
Converting the metal oxide precursor and the metal element precursor into the metal oxide and the metal element, respectively, further comprising a third step.
12. The method for producing an integrated catalyst according to 0 or 11. 13. The method according to claim 12, wherein the third step is repeated a plurality of times. 14. The method for producing an integrated catalyst according to claim 9, wherein the third step is performed at least once while repeating the multi-step step in the second step. 15. The first element in which a gold element is supported on diiron trioxide
A catalyst unit group comprising a large number of catalyst units, a second catalyst unit in which platinum element is supported on tin dioxide, and a catalyst unit group including a large number of third catalyst units in which iridium element is supported on lanthanum oxide; A method for producing an integrated catalyst in which two catalyst components and the third catalyst component are assembled at the nanometer level to form the catalyst unit group, wherein the trioxide is integrated at the nanometer level. Preparing an aqueous solution containing ferrous iron and the tin dioxide; dissolving a platinum compound in the aqueous solution; and adjusting the pH of the aqueous solution.
Is set on the more alkaline side than the isoelectric point of the tin dioxide and on the more acidic side than the isoelectric point of the diiron trioxide to selectively convert platinum cations from the platinum compound to the tin dioxide only. Adhering, adjusting the pH of the aqueous solution to be more alkaline within a range not exceeding the isoelectric point of the diiron trioxide to induce platinum hydroxide from the platinum cation, and heat treating the platinum hydroxide. And converting to the platinum element, dissolving a gold compound in the aqueous solution and setting the pH of the aqueous solution between the isoelectric point of the tin dioxide and the isoelectric point of the diiron trioxide, Selectively adhering gold anions from the gold compound only to the diiron trioxide, further adjusting the pH of the aqueous solution to an alkaline side to induce gold hydroxide from the gold anions, Heat treatment of gold oxide Converting lanthanum salt and iridium salt into the aqueous solution, adjusting the pH of the aqueous solution to generate lanthanum hydroxide and iridium hydroxide in the aqueous solution, Heating the lanthanum oxide and the iridium hydroxide to convert them to the lanthanum oxide and the iridium element, respectively.