JP2001096158A - Methanol reforming catalyst system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a methanol reforming catalyst converting all supplied methanol into hydrogen-containing gas, and reducing the generation amount of CO and increasing the amount of hydrogen. SOLUTION: In a methanol reforming catalyst system, a methanol steam reforming reaction catalyst or a partial oxidation reaction concurrently causing catalyst which concurrently causes a methanol steam reforming reaction and a partial oxidation reaction is disposed at the front side with respect to the flow direction of a methanol-containing fluid, and a methanol steam reforming reaction and methanol decomposition reaction concurrently causing catalyst is disposed at the rear side.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a methanol reforming catalyst, and more particularly, to a process for producing hydrogen by steam reforming of methanol, or a process in which steam reforming of methanol and a partial oxidation reaction of methanol are performed simultaneously. In the process of producing hydrogen, the entire amount of methanol is completely reacted, and 95% or more of the product gas is hydrogen,
The present invention relates to a catalyst system such as a catalyst system and a catalyst device that can be converted into carbon dioxide and water.

[0002]

2. Description of the Related Art Hitherto, processes for reforming methanol and converting it to a hydrogen-containing gas have been widely applied to fuel cells, liquid hydrogen production, and the like. The methanol reforming process usually involves a methanol steam reforming reaction as a main reaction. Here, carbon monoxide (CO), which is a catalyst poison to the fuel cell electrode, is used.
Is hardly generated. As a catalyst used in the present process, Cu or a copper-based (Cu) catalyst centered on Cu and Zn is used, and about 95% of methanol reacts by a steam reforming reaction.
A hydrogen-containing gas is produced. At this time, the CO generation concentration can be set to about 1% or less.

However, the conversion efficiency of methanol is 95%.
At about%, when the present methanol reformer system is applied to a polymer electrolyte fuel cell system, unreacted methanol flows into the downstream fuel cell system. Then, the residual methanol in the reformed gas becomes a poisoning substance that inhibits the reaction of the electrode similarly to carbon monoxide, and thus becomes a catalyst poison for the electrode, and the reforming catalyst as described above is directly used in the fuel cell system. There was a problem that it could not be done. Therefore, there is a need for a methanol reforming system with even higher methanol conversion efficiency.

On the other hand, the methanol steam reforming reaction is a large endothermic reaction as represented by the following formula. In a system in which heat is not supplied from the outside to the catalyst, the temperature of the catalyst layer is lowered and the reaction activity is reduced. I do. CH ₃ OH + H ₂ O → CO ₂ + 3H ₂ − 11.8kcal / mol

Therefore, in order to increase the reaction activity, oxygen is newly added to water / methanol as a raw material, so that a methanol steam reforming reaction and a methanol partial oxidation reaction, which is an exothermic reaction, are simultaneously carried out, so that steam reforming is performed. Systems that compensate for the endothermic nature of the reaction are being studied. But,
Even in this method, it is difficult to make the conversion efficiency (reformation rate) of methanol 100%, and unreacted methanol remains.

[0006]

SUMMARY OF THE INVENTION In view of the above problems, the present inventors convert all of the supplied methanol into synthesis gas, which is a hydrogen-containing gas, and generate C
We studied diligently to develop a catalyst system that reduces the amount of O and increases the amount of hydrogen. As a result, the present inventors arranged a catalyst for mainly performing the methanol steam reforming reaction and the methanol partial oxidation reaction in the upstream part with respect to the gas flow direction of the catalyst layer, and provided the methanol in the downstream part. The inventors have found that a catalyst system in which a catalyst for mainly performing a steam reforming reaction and a methanol decomposition reaction is disposed is effective, and have completed the present invention.

[0007]

That is, according to the present invention, a methanol steam reforming reaction catalyst is disposed in a preceding stage in a flow direction of a fluid containing methanol, and a methanol steam reforming reaction and a methanol cracking reaction occur simultaneously in a subsequent stage. It is intended to provide a catalyst system for methanol reforming, wherein a catalyst is arranged. Further, the methanol steam reforming reaction catalyst in the former stage may be a partial oxidation reaction co-catalyst that causes a methanol steam reforming reaction and a partial oxidation reaction to occur simultaneously. Here, the methanol steam reforming reaction catalyst at the former stage contains at least one or more metals selected from the group consisting of copper, chromium, zinc and iron, and contains at least one metal selected from aluminum, zirconium, gallium, alkaline earth metals and rare earths. It is preferable to contain an oxide of at least one element selected from the group consisting of, for example, (i) copper, zinc and aluminum, gallium or zirconium, and alkaline earth. An embodiment containing one or more elements of a class of metals and rare earths, (ii) an embodiment containing chromium and zinc, and containing an oxide of one or more of aluminum, zirconium, alkaline earth metals and rare earths, Or (iii) contains chromium and iron, and contains aluminum, zirconium, alkaline earth metal or the like. Embodiments containing an oxide of one or more elements from the fine rare earth, and the like. Further, it is preferable that the methanol steam reforming reaction catalyst in the first stage is made of an amorphous oxide and has a specific surface area of at least 30 m ² / g or more.

[0008] Further, the latter-stage catalyst for simultaneous methanol reforming of methanol and methanol decomposition reaction contains an oxide containing aluminum oxide as a main component (50% by weight or more) and is composed of platinum, palladium and rhodium. It is preferable that at least one element selected from the group consisting of platinum, palladium and rhodium is added in an amount of 0.1 to 10 m with respect to the total amount of the oxide.
Preferably, the concentration is ol%. Further, it is preferable that the subsequent-stage catalyst for simultaneous methanol reforming of methanol and methanol decomposition reaction is made of an amorphous oxide and has a specific surface area of at least 30 m ² / g or more. Further, the oxide containing aluminum oxide as a main component may contain zirconium oxide or lanthanum oxide.

As described above, the present invention provides a catalyst for methanol steam reforming having the above characteristics alone or a catalyst capable of simultaneously performing the methanol steam reforming reaction and the partial oxidation reaction. And a catalyst for simultaneous methanol reforming reaction. A catalyst system in which a methanol steam reforming reaction catalyst capable of causing the partial oxidation reaction is arranged upstream of the flow of the fluid, and the methanol decomposition reaction combined catalyst is arranged downstream of the flow of the fluid. Is provided.

According to the catalyst system of the present invention, extremely high methanol conversion efficiency can be realized, so that all of methanol can be reacted stably and a reformed gas having a high hydrogen content can be obtained. Therefore, a hydrogen-containing gas suitably used for a fuel cell can be obtained.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The methanol reforming catalyst system of the present invention has a methanol-based steam reforming catalyst such as a Cu-based catalyst arranged in the front stage and a noble metal-containing catalyst in the rear stage in the flow direction of the fluid containing methanol. A catalyst for simultaneous decomposition of methanol, which is a catalyst, is provided. In the present embodiment, in order to remove unreacted methanol at the reformer catalyst outlet,
By disposing a noble metal-containing catalyst such as Pt / Al ₂ O ₃ on the downstream side of the Cu-based catalyst, unreacted methanol at the outlet of the Cu-based catalyst is completely decomposed and removed. In the present invention, the use of the catalyst system in two stages of the former stage and the latter stage has the following effects. That is, the Cu-based catalyst has a feature that it generates a large amount of hydrogen and a small amount of CO. That is, among the following reactions (1) and (2), there is a function of causing the reforming reaction (1) to proceed preferentially. However, from the viewpoint of completely reforming methanol, the activity as a catalyst is insufficient, and unreacted methanol remains.

CH ₃ OH + H ₂ O → CO ₂ + 3H ₂ (1) CH ₃ OH → CO + 2H ₂ (2) On the other hand, the catalyst having a noble metal-based active component such as Pt is described above. (1) Of the reactions of (2), the reforming reaction of (2) preferentially proceeds to decompose methanol, and this reaction has an excellent catalytic activity to almost completely decompose methanol. Have. That is, the activity (conversion rate) of the methanol decomposition reaction is about 95% for the Cu-based catalyst, and exceeds 99% for the noble metal-based catalyst due to the reaction (2). However, on the other hand, the reaction (2) alone generates a large amount of CO that inhibits the electrode reaction of the fuel cell, and the amount of hydrogen obtained is undesirably reduced as compared with the reaction (1).

For this reason, in the present embodiment,
Prior to the catalyst system, methanol is reacted as much as possible with a catalyst such as Cu or Cu—Zn to generate more hydrogen. Next, in the subsequent subsequent stage, all the unreacted residual methanol in the previous reaction is removed by a decomposition reaction using a noble metal-based catalyst. Here, in the reaction of (2) using the noble metal catalyst in the latter stage, CO 2
However, since the amount of unreacted methanol in (1) itself is small, this is not a problematic level. With this configuration, in the present invention, the amount of hydrogen obtained can be increased, the amount of CO can be reduced, and unreacted methanol can be reduced as much as possible.

According to the present invention, a methanol steam reforming reaction catalyst (which may be a catalyst accompanied by partial oxidation reaction) at the preceding stage is provided.
This is a catalyst system comprising a combination of a later-stage catalyst for simultaneous reforming of methanol and a decomposition reaction of methanol. The catalyst at the former stage is composed of a composite oxide, and each component also acts as an active metal, and for example, copper oxide-zinc oxide-aluminum oxide and the like integrally act as a catalyst. In the reaction using this catalyst, CO is not generated and a large amount of hydrogen is generated, but a small amount of unreacted methanol remains.

The methanol steam reforming reaction catalyst in the first stage contains at least one metal selected from the group consisting of copper, chromium, zinc and iron, and contains aluminum, zirconium, gallium, alkaline earth metals and rare earths. It is preferable to contain an oxide of at least one element selected from the group consisting of: Specifically, for example, (i) a catalyst system containing copper, zinc and aluminum, and containing gallium or zirconium, and containing one or more elements of alkaline earth metals and rare earths,
(ii) a catalyst system containing chromium and zinc and containing an oxide of one or more of aluminum, zirconium, alkaline earth metals and rare earths, or (i.
ii) A catalyst system containing chromium and iron and containing an oxide of one or more of aluminum, zirconium, alkaline earth metals and rare earths is preferably used. The methanol steam reforming reaction catalyst in the former stage is made of an amorphous oxide and has a specific surface area of at least
It is preferably at least 30 m ² / g.

In the present invention, in the catalyst system at the preceding stage,
Either the case where the partial oxidation reaction occurs or the case where the partial oxidation reaction does not occur can be applied, and the methanol steam reforming reaction catalyst used in the preceding stage can also cause the partial oxidation reaction (3). Therefore, when oxygen is supplied as a raw material, the following reactions (1) and (3) proceed simultaneously.

CH ₃ OH + H ₂ O → CO ₂ + 3H ₂ -Q (1) CH ₃ OH + 1 / 2O ₂ → CO ₂ + 2H ₂ + Q (3) Here, in the methanol reforming, The steam reforming reaction of 1) is a considerable endothermic reaction, and it is effective to supply heat to increase the reaction efficiency, while the reaction of (3) is an exothermic reaction, and a considerable amount of heat is released by the reaction. I do. Therefore, by performing these reactions simultaneously,
As a whole, it works in a direction in which the calorie balance is maintained, and methanol reforming is performed efficiently.

In the catalyst system in the latter stage in the present embodiment,
By the noble metal catalyst, the methanol steam reforming reaction of the following formula (1) and the methanol decomposition reaction of the following formula (2) proceed. CH ₃ OH + H ₂ O → CO ₂ + 3H ₂ -Q (1) CH ₃ OH → CO + 2H ₂ (2) The oxide of the latter catalyst mainly contains aluminum oxide (50
% By weight or more), and zirconium oxide, lanthanum oxide, and the like can be appropriately added thereto for the purpose of improving heat resistance. The latter catalyst system has higher reaction activity than the former catalyst system, and decomposes and removes unreacted methanol remaining in the former reaction. Although CO is generated in the subsequent methanol decomposition reaction, most of the methanol can be decomposed and removed, which is advantageous for the whole system.

As the catalyst for the simultaneous methanol steam reforming reaction and methanol decomposition reaction in the latter stage, a catalyst containing an oxide containing aluminum oxide as a main component (50% by weight or more) and containing platinum, palladium and rhodium is used. It is preferable that at least one selected element is contained as an active species. In this case, the sum of the platinum, palladium and rhodium elements (the total amount of the active components) is the total amount of the oxide (the total amount of the carrier). Preferably, the concentration is 0.1 to 10 mol%. Here, the methanol decomposition reaction (removal) catalyst is obtained by dispersing a precious metal such as Pt, Ru, Pd or the like alone or alloyed as a catalyst component on a support of a metal oxide or a composite oxide such as alumina or zirconia. It can be used by carrying and pelletizing or honeycombing.

According to the above-described catalyst system including the former stage and the latter stage, methanol can be completely reformed by the reforming reaction by the catalyst system. Therefore, an apparatus for removing methanol by post-treatment is not required. Therefore, when combined with another system, it is extremely useful in terms of downsizing and efficiency. Hereinafter, specific examples of a method for preparing a catalyst according to the present invention will be described in detail.

First, a method for preparing a single catalyst for methanol steam reforming reaction or a catalyst for simultaneous methanol steam reforming reaction and partial oxidation reaction is as follows: an aqueous metal salt solution is coprecipitated with alkali, and the resulting catalyst precursor is calcined. And a method of mixing a metal salt aqueous solution, evaporating the mixture to dryness, and baking. Any method may be used as long as the oxide constituting the catalyst is amorphous, but the coprecipitation method is particularly preferable. When prepared by the coprecipitation method, the precipitant aqueous solution is kept warm, and while stirring, contains one or more of copper, chromium, zinc, iron, and aluminum, zirconium, gallium, alkaline earth metal and An aqueous solution of one or more metal salts from among the rare earths is dropped to form a precipitate. Here, the order of dropping the metal salt is not particularly limited, but for a catalyst containing copper, it is preferable to drop the aqueous copper metal salt solution last. In addition, almost all of the metal ions dropped when the pH at the end of the dropping is 4 or more are precipitated as precipitates.

The aqueous solution of the precipitating agent is an alkaline solution, and usually, sodium carbonate, sodium hydrogencarbonate, sodium hydroxide, potassium carbonate, aqueous ammonia and the like having a concentration of 0.1 to 10 M are used, and sodium carbonate is particularly preferable.
In addition, it is preferable to maintain the temperature of the solution at the time of forming the precipitate in the range of 15 to 90 ° C. Further, each metal salt as a catalyst component is contained in the form of nitrate, chloride, sulfate, acetate in the form of 0.0
It is preferably used as an aqueous solution having a concentration of 1 to 1.0 M, particularly preferably as a nitrate. The dropping time and the aging time do not particularly affect the methanol synthesizing activity of the catalyst, but may be any conditions under which metal ions are uniformly dispersed and precipitates are deposited. Usually, the dropping time is 1 minute to 3 hours, and the aging time is 1 minute. It is carried out in the range of minutes to 3 hours. Although the obtained precipitate has various crystal seeds, it is calcined at 200 to 500 ° C. after sufficiently removing alkali metal ions by washing.

Next, a method for preparing a catalyst for simultaneous steam reforming and decomposition of methanol is described in which zirconium oxide, aluminum oxide, lanthanum oxide, or a composite oxide thereof is used as a carrier and platinum, rhodium, palladium is added thereto. The method of impregnating or applying the metal salt solution of above, drying and firing is preferred. In the case of preparing a composite oxide of zirconium oxide, aluminum oxide, and lanthanum oxide, the following method is preferable. A metal salt of γ-alumina, boehmite or aluminum is dispersed or mixed in water, and a solution in which a metal salt of zirconium and / or lanthanum is dissolved is kept warm, and an aqueous ammonia solution is added dropwise with stirring to form a precipitate. Note that almost all of the metal ions dropped when the pH at the end of dropping is 6 or more are precipitated as precipitates. The aluminum metal salt is used in the form of nitrate, chloride, sulfate or acetate as an aqueous solution having a concentration of 0.01 to 1.0 M, and is particularly preferably used as nitrate. Further, zirconium and lanthanum metal salts are used in the form of nitrates, chlorides, sulfates and acetates as aqueous solutions having a concentration of 0.01 to 1.0 M, and particularly preferably as nitrates.

The temperature of the solution at the time of forming the precipitate is 1
It is preferable to keep the temperature in the range of 5 to 90 ° C. The dropping time and the aging time are not particularly limited, but may be any conditions under which the raw material for the precipitation is uniformly dispersed and the precipitate is precipitated, and usually ranges from 1 minute to 3 hours to the dropping time and 1 minute to 3 hours. Will be implemented. Although the obtained precipitate has various crystal seeds, when chlorides and sulfates are used as metal salts, after sufficiently removing chloride ions and sulfate ions, 300 to 800
Fired in the ° C range. Further, regarding the catalyst system combining the above catalysts, the ratio of the catalyst in the upstream part to the catalyst in the downstream part and the shape of each catalyst are not particularly limited, but the shapes are pellet-like, honeycomb-like. It is preferably used in the form of By using the catalyst according to the present invention, all of the methanol can be reacted stably and a reformed gas having a high hydrogen content can be obtained. Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

[0025]

[Example] Example 1 A catalyst of a methanol steam reforming reaction alone, or a catalyst of a methanol steam reforming reaction and a partial oxidation reaction simultaneous reaction type was used.
It was prepared as follows. Dissolve 30 mol of sodium carbonate in 15 liters of water and keep the temperature at 50 ° C. This alkali aqueous solution is designated as A. 6 mol of zinc nitrate, 4 mol of aluminum nitrate or 12 mol of copper nitrate were dissolved in 5 liters of water, and acid solutions kept at 50 ° C. were respectively dissolved in solutions B, C,
D. Then, the solutions B, C, and D are uniformly dropped into the solution A in the order of the solutions B, C, and D over 30 minutes with stirring to obtain a precipitate forming solution. Next, aging was performed for 2 hours, and the precipitate was filtered.
₃ Wash so that no ions can be detected.
After drying for 3 hours and calcining at 300 ° C for 3 hours, the catalyst 1
I got

In a similar manner, 7 mol of zinc nitrate, 2.8 mol of aluminum nitrate, 0.8 mol of gallium nitrate and 0.2 mol of magnesium nitrate are added to an aqueous sodium carbonate solution.
mol was dissolved in 5 liters of water, and then a solution prepared by dissolving 11 mol of copper nitrate in 5 liters of water was added dropwise.
The resulting precipitate was filtered, washed, dried and calcined to obtain Catalyst 2. Catalysts 3 and 4 were also obtained by a method in which an aqueous solution of copper nitrate was dropped independently and finally. As for the catalyst 5, 30 mol of sodium carbonate was dissolved in 15 liters of water, and an aqueous solution in which 9 mol of zinc nitrate, 9 mol of chromium nitrate, and 2 mol of aluminum nitrate were dissolved in 5 liters of water was added dropwise over 30 minutes. The solution was filtered, washed, dried, and calcined at 400 ° C. for 5 hours to obtain a solution. Catalyst 6 was also obtained in the same manner as for catalyst 5, except that zinc nitrate was replaced with iron nitrate and aluminum nitrate was replaced with zirconium nitrate. Table 1 shows a list of the prepared catalysts for methanol steam reforming alone or simultaneously with methanol steam reforming reaction and partial oxidation reaction.

[0027]

[Table 1] Note) Numbers in parentheses indicate mol% of oxide.

Example 2 A catalyst for simultaneous steam reforming of methanol and methanol decomposition was prepared as follows. After mixing and dissolving 11 mol of aluminum nitrate and 0.5 mol of zirconium nitrate in 10 liters of ion-exchanged water, a 1N aqueous ammonia solution is added dropwise with stirring until the pH in the system becomes 9.0. The precipitate obtained by this operation is filtered,
After drying, baking at 500 ° C for 5 hours, zirconia
An alumina composite oxide was obtained. Also, aluminum nitrate 1
Except that 7 mol, 1 mol of zirconium nitrate, and 0.6 mol of lanthanum nitrate were dissolved in 20 liters of ion-exchanged water, a lanthania-zirconia-alumina composite oxide was obtained in the same manner as in the case of the zirconia-alumina composite oxide. . Furthermore, 16 mol of aluminum nitrate,
A lanthania-alumina composite oxide was obtained in the same manner as in the case of the zirconia-alumina composite oxide, except that 3 mol of lanthanum nitrate was dissolved in 20 liters of ion-exchanged water.

Next, 0.25 mol of a chloroplatinic acid solution was impregnated into the zirconia-alumina composite oxide, dried and calcined at 500 ° C. for 5 hours to obtain a catalyst 7. Also 0.2
mol of rhodium chloride solution was impregnated with the above-mentioned lanthania-zirconia-alumina composite oxide, dried and calcined at 500 ° C. for 5 hours to obtain catalyst 8. Further, a 0.5 mol of palladium nitrate solution was impregnated into the above-mentioned lanthania-alumina composite oxide, dried, and calcined at 500 ° C. for 5 hours to obtain a catalyst 9. Table 2 shows a list of the prepared methanol steam reforming and decomposition simultaneous catalysts.

[0030]

[Table 2] Note) Numbers in parentheses indicate mol% of oxide.

Example 3 As a catalyst system, each of the above catalyst systems was arranged as follows. That is, catalysts 10 to 15 were obtained by disposing the catalyst shown in Example 1 on the upstream side with respect to the gas flow direction and disposing the catalyst shown in Example 2 on the downstream side. Table 3 below shows a list of catalyst systems.

[0032]

[Table 3]

Example 4 The catalyst system in Example 3 was evaluated by steam reforming with methanol. The evaluation method uses a flow-type microreactor, vaporizes a certain amount of water-methanol solution, mixes this with a certain amount of air, circulates the mixed gas through the catalyst layer, and analyzes the gas composition at the catalyst layer outlet. The methanol conversion was calculated by the equation.

[0034]

(Equation 1) The reaction conditions are shown in Table 4, and the results of evaluating the methanol conversion activity of Catalysts 10 to 15 and Comparative Catalysts 1 to 3 are shown in Table 5.

[0035]

[Table 4]

[0036]

[Table 5] From the results in Table 5, the catalyst systems of the catalysts 10 to 15 have a methanol conversion of 100%, and the comparative catalysts 1 to 3 have a methanol conversion of about 90 to 95%, so that the catalyst of the present invention is effective. It was shown that.

Example 5 The catalyst in Example 3 was evaluated by simultaneously performing the methanol partial oxidation and the steam reforming reaction. The evaluation method was the same as in Example 4, using a flow-through microreactor, vaporizing a certain amount of water-methanol solution, mixing a certain amount of air with the solution, and flowing the mixed gas through the catalyst layer.
The gas composition at the outlet of the catalyst layer was analyzed to calculate the methanol conversion. The reaction conditions are shown in Table 6, and the results of evaluating the methanol conversion activity of Catalysts 10 to 15 and Comparative Catalysts 1 to 3 are shown in Table 7.

[0038]

[Table 6]

[0039]

[Table 7] The results in Table 7 show that the catalyst systems of Catalysts 10 to 15 had a methanol conversion of 100%, indicating that the catalyst of the present invention was effective.

[0040]

According to the present invention, it is possible to convert the entire amount of supplied methanol to a synthesis gas which is a hydrogen-containing gas, to reduce the amount of generated CO, and to increase the amount of hydrogen. And, according to the catalyst system of the present invention, since extremely high methanol conversion efficiency can be realized, all methanol can be reacted stably,
Further, a reformed gas having a high hydrogen content is obtained, and is suitably used in a fuel cell system or the like.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (Reference) B01J 23/86 B01J 23/82 MF term (Reference) 4G069 AA20 BA01A BA05A BA17 BB04A BB12B BB16B BC02B BC08A BC10B BC16B BC17A BC17B BC31A BC31B BC35A BC35B BC42B BC51A BC51B BC58A BC58B BC66A BC66B BC71A BC72A BC75A CC17 DA10 EE05 EE09

Claims (7)

[Claims] Claims: 1. A methanol steam reforming reaction catalyst is disposed at a preceding stage with respect to the flow direction of a fluid containing methanol,
A catalyst system for methanol reforming, wherein a catalyst for simultaneous steam reforming of methanol and methanol decomposition reaction is disposed in a subsequent stage. 2. The methanol reforming reaction according to claim 1, wherein the methanol steam reforming reaction catalyst in the first stage is a partial oxidation reaction co-catalyst in which a methanol steam reforming reaction and a partial oxidation reaction occur simultaneously. Catalyst system. 3. The methanol steam reforming reaction catalyst of the preceding stage contains at least one metal selected from the group consisting of copper, chromium, zinc and iron, and contains aluminum, zirconium, gallium, alkaline earth metal and 3. An oxide of at least one element selected from the group consisting of rare earths.
The catalyst system for methanol reforming according to 1. 4. The methanol steam reforming reaction catalyst of the preceding stage is made of an amorphous oxide and has a specific surface area of at least 30.
The catalyst system for methanol reforming according to claim 1 or 2, wherein the catalyst system has a m ² / g or more. 5. A catalyst for simultaneous methanol steam reforming reaction and methanol decomposition reaction in the latter stage containing at least one oxide containing aluminum oxide as a main component and at least one selected from the group consisting of platinum, palladium and rhodium. The catalyst system for methanol reforming according to claim 1, comprising the following element: 6. The catalyst system for methanol reforming according to claim 5, wherein the sum of the respective elements of platinum, palladium and rhodium is 0.1 to 10 mol% based on the total amount of the oxide. . 7. The method according to claim 1, wherein the catalyst for simultaneous methanol steam reforming reaction and methanol decomposition reaction in the latter stage comprises an amorphous oxide and has a specific surface area of at least 30 m ² / g. The catalyst system for methanol reforming according to 1.