JP2001232193A - Methanol reforming catalyst and methanol reforming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce a methanol reforming catalyst having improved heat resistance and improved methanol conversion when a steam reforming reaction of methanol is performed at a high temperature of >=300 deg.C and the methanol steam reforming reaction and a methanol oxidation reaction are performed at a high temperature of >=300 deg.C, so as to be low in the concentration of Co in the produced hydrogen-containing gas and further unnecessary for activation process. SOLUTION: The methanol reforming catalyst has methanol steam reforming reaction activity and contains a carrier composed of an amphoteric oxide or a composite oxide of the amphoteric oxide with an active species carried on the carrier and containing a Pd component.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a methanol reforming catalyst having a methanol steam reforming reaction activity, and to a methanol reforming method for producing an H ₂ -containing gas using the methanol reforming catalyst.

[0002]

2. Description of the Related Art In recent years, fuel cells have been attracting attention as a method for efficiently and cleanly producing electric energy in the face of increasing global environmental problems. In particular, since exhaust gases emitted from internal combustion engines such as automobiles contain a large amount of harmful gases such as nitrogen oxides and carbon monoxide, various measures have been taken. As one of the improvement measures, development of a vehicle equipped with a polymer electrolyte fuel cell (PEFC) instead of an internal combustion engine has been earnestly pursued.

In a polymer electrolyte fuel cell (PEFC), a fuel gas mainly composed of hydrogen (H ₂ ) is diffused as protons in a polymer membrane, and electric energy is obtained from the movement of electrons accompanying the diffusion. Efficient hydrogen production equipment is required for mounting on vehicles. In addition, a platinum catalyst is mainly used for the electrodes of the polymer electrolyte fuel cell. Since platinum catalysts are easily poisoned by carbon monoxide (CO),
It is necessary to remove CO from fuel gas as much as possible. Methanol is frequently used as a fuel gas raw material. Methanol is an inexpensive liquid fuel that is easily synthesized from fossil fuels, and has the feature that it can be relatively easily converted to hydrogen using a catalyst.

As a method for producing hydrogen from methanol, a steam reforming reaction as shown in the following formula (1) is known. However, this reaction is a relatively large endothermic reaction. In addition, a method of simultaneously causing a partial oxidation reaction of methanol as shown in the formulas (2) to (4) is often used.

CH ₃ OH + H ₂ O → 3H ₂ + CO ₂ −11.8 kcal / mol (1) CH ₃ OH + 1 / 2O ₂ → CO ₂ + 2H ₂ +11.8 kcal / mol (2) CH ₃ OH + 1 / 2O ₂ → CO + H ₂ + H ₂ O + 11.8 kcal / mol (3) CH ₃ OH + O ₂ → CO ₂ + H ₂ + H ₂ O + 11.8 kcal / mol (4) As a catalyst for this steam reforming reaction, zinc oxide ( Zn
A carrier in which copper oxide (CuO) is supported on a carrier made of O) is known.

However, since the activity of this CuO / ZnO catalyst is low when CuO is used as it is, an activation treatment by a reduction treatment is necessary. When the catalyst is exposed to the atmosphere after the activation treatment, the catalyst is reoxidized. Therefore, it is necessary to handle in an oxygen-free atmosphere, and there is a problem that the operation of charging the catalyst becomes complicated. Further, the CuO / ZnO catalyst has a problem that when the reaction temperature of the steam reforming reaction is 280 ° C. or higher, the activity is reduced due to copper sintering (semi-melting) and the amount of CO generated is increased. Have.

[0007] By the way, the 58th Catalysis Conference A of the Catalysis Society of Japan
(Nagoya, October 1986), Kasaoka et al., Department of Precision and Applied Science, Faculty of Engineering, Okayama University. (1991), pp. 297-303), mainly a Pt (partially Rh, Pd, Ru) supported catalyst (support: Al ₂ O ₃ (γ, α), CaO, Ce)
O ₂ , Cr ₂ O ₃ , La ₂ O ₃ , MgO, Nb ₂ O ₅ , Si
O ₂ , TiO ₂ (anatase), Y ₂ O ₃ , ZnO and Zr
O ₂ ), and a methanol decomposition reaction (CH ₃ OH = CO + 2H ₂ ) is described using this catalyst.

[0008]

SUMMARY OF THE INVENTION The present invention relates to a catalyst for improving the heat resistance of a catalyst, wherein a methanol steam reforming reaction is carried out at a high temperature of 300 ° C. or higher, and a methanol steam reforming reaction is carried out at a high temperature of 300 ° C. or higher. Also, the present invention provides a methanol reforming catalyst and a methanol reforming method in which the methanol conversion rate at the time of performing a methanol oxidation reaction is improved, the CO concentration in the generated hydrogen-containing gas is low, and the activation treatment step is unnecessary. The purpose is to:

[0009]

The methanol reforming catalyst according to the present invention comprises a methanol steam reforming reaction (CH ₃ OH).
+ H ₂ O → CO ₂ + 3H ₂ ) A methanol reforming catalyst having activity, comprising an amphoteric oxide or a composite oxide of an amphoteric oxide, a carrier supported on the carrier, and an active species containing a Pd component And is characterized by containing.

The methanol reforming catalyst according to the present invention comprises a methanol steam reforming reaction (CH ₃ OH + H ₂ O → CO ₂ +
3H ₂ ) A methanol reforming catalyst having an activity and causing an oxidation reaction of methanol as a side reaction,
A carrier comprising an amphoteric oxide or a composite oxide of an amphoteric oxide, and an active species supported on the carrier and containing a Pd component.

The method for reforming methanol according to the present invention comprises:
Tanol steam reforming reaction (CH_ThreeOH + H_TwoO → CO_Two+
3H_Two) Active methanol reforming catalyst and CH_ThreeOH and
And H _TwoBoth the raw material gas containing O and the
From the raw material gas by the_TwoContaining gas
In the methanol reforming method for producing, the methanol
The reforming catalyst is an amphoteric oxide or a compound of an amphoteric oxide.
A carrier comprising a composite oxide; and a Pd component supported on the carrier.
And an active species containing
You.

The method for reforming methanol according to the present invention is characterized in that
A raw material gas containing H ₃ OH, H ₂ O and O ₂ is subjected to a methanol steam reforming reaction (CH ₃ OH +
H ₂ O → CO ₂ + 3H ₂ ) and a methanol oxidation reaction as a side reaction, and the heat of formation of the oxidation reaction is used as the heat of reaction of the steam reforming reaction to remove H ₂ from the raw material gas. In the methanol reforming method for producing a contained gas, the methanol reforming catalyst may be an amphoteric oxide or a support made of a composite oxide of an amphoteric oxide, and an active species supported on the support and containing a Pd component. It is characterized by including.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a methanol reforming catalyst according to the present invention will be described.

This methanol reforming catalyst is a catalyst having a methanol steam reforming reaction (CH ₃ OH + H ₂ O → CO ₂ + 3H ₂ ) activity, and comprises an amphoteric oxide or a composite oxide of amphoteric oxide. A carrier; and an active species supported on the carrier and containing a Pd component. This methanol reforming catalyst is used for a methanol steam reforming reaction (CH ₃ OH + H ₂
O → CO ₂ + 3H ₂ ) In addition to the activity, it may be one that causes an oxidation reaction of methanol as a side reaction when an oxygen gas is contained in the raw material gas. Examples of the methanol oxidation reaction include a partial oxidation reaction and a complete oxidation reaction shown in the following (a) to (c).

CH ₃ OH + 1 / 2O ₂ → CO ₂ + 2H ₂ +11.8 kcal / mol (a) CH ₃ OH + 1 / 2O ₂ → CO + H ₂ + H ₂ O + 11.8 kcal / mol (b) CH ₃ OH + O ₂ → CO ₂ + H ₂ + H ₂ O + 11.8 kcal / mol (c) The carrier is composed of ZnO, CeO ₂ , Al ₂ O ₃ , SnO _x (where x indicates x> 0), TiO ₂ and ZrO ₂ Or an amphoteric oxide selected from the group consisting of ZnO, CeO ₂ , Al ₂ O ₃ , and SnO _x (where x>x>
0), a composite oxide of two or more amphoteric oxides selected from the group consisting of TiO ₂ and ZrO ₂ . Among them, ZnO, or a single CeO _2, or be a composite oxide of ZnO and CeO ₂ are preferred.

As the Pd component contained in the active species, the following (A) or (B) can be used.

(A) The Pd component comprises at least one selected from Pd and PdO. This Pd component is
The morphology changes before and after the methanol steam reforming reaction. That is, after the catalyst is prepared, it is reduced by PdO with H ₂ generated by the steam reforming reaction of methanol as shown in the following formula (d) until the steam reforming reaction of methanol is performed, and the stability in the air is obtained. During the steam reforming reaction of methanol and after the reaction, it is composed of Pd alone or both Pd alone and PdO. Note that P
Since H ₂ consumed by the reduction of dO is very small, H ₂
Has little effect on production.

PdO + ／ H ₂ → Pd + H ₂ O (d) (B) The Pd component is Pd in an alloy containing Pd. As an alloy containing Pd, for example, Pd and P
alloy consisting of t, alloy consisting of Pd and Cu, Pd, Pt
And Cu alloys.

It is desirable that the content of the Pd component in the methanol reforming catalyst is in the range of 0.1 to 10% by weight in terms of Pd element. This is due to the following reasons. If the content is less than 0.1% by weight, it is difficult to sufficiently increase the steam reforming reaction activity, and the CO concentration in the product gas may increase. On the other hand, when the content is 10
If the content is more than 10% by weight, the occupancy of the carrier in the catalyst decreases, the steam reforming reaction activity decreases, and the CO concentration in the product gas may increase. A more preferable range of the content is Pd
It is 0.5 to 8% by weight in terms of element.

Next, a methanol reforming method using the above-described methanol reforming catalyst will be described. Examples of the methanol reforming method include the method described in the following (1) or (2).

(1) The methanol reforming catalyst according to the present invention and a raw material gas containing CH ₃ OH and H ₂ O are heated, and a steam reforming reaction is caused by the methanol reforming catalyst. generating of H ₂ containing gas from.

(2) Among the methanol reforming catalysts according to the present invention, those which cause a methanol oxidation reaction in a side reaction are prepared, and the raw material gas containing CH ₃ OH, H ₂ O and O ₂ is added to the methanol reforming catalyst. Causes a methanol steam reforming reaction and a methanol oxidation reaction as a side reaction to generate an H ₂ -containing gas from the raw material gas.

Since the methanol steam reforming reaction is an endothermic reaction, it is necessary to supply reaction heat. (1) mentioned above
In the above method, heat is supplied from the outside by heating the heater. On the other hand, in the method (2), the heat generated by the methanol oxidation reaction (exothermic reaction) is used as the reaction heat of the methanol steam reforming reaction (endothermic reaction). Further, the heater may be heated together with the use of the heat generated by the oxidation reaction.

In the reactions (1) and (2),
It is preferable to maintain the temperature of the methanol reforming catalyst in the range of 300 to 500C. This is due to the following reasons. When the catalyst temperature is lower than 300 ° C., the steam reforming activity of the catalyst is reduced, so that a high methanol conversion rate cannot be obtained, and the CO concentration in the generated hydrogen-containing gas may increase. On the other hand, when the catalyst temperature exceeds 500 ° C., a decomposition reaction of methanol (CH ₃ O
H → CO + 2H ₂ ) is likely to occur, and the CO concentration in the hydrogen-containing gas may increase. A more preferable range of the reaction temperature is 300 to 380 ° C.

The methanol reforming catalyst and the methanol reforming method according to the present invention are used, for example, when producing a fuel gas containing hydrogen as a main component for a polymer electrolyte fuel cell.

According to the methanol reforming catalyst of the present invention described in detail above, the following effects (1) and (2) can be obtained.

(1) In a high-temperature environment of 300 ° C. or higher, it is possible to suppress the occurrence of thermal deterioration such as sintering (semi-melting), and to reduce the steam reforming reaction activity at a high temperature of 300 ° C. or higher. Can be made higher than the CuO / ZnO catalyst and the catalyst whose active species is Pt. As a result, the methanol conversion rate at the time of performing the methanol reforming reaction at a high temperature of 300 ° C. or higher can be improved, and the CO concentration of the product gas containing hydrogen as a main component can be reduced. Thus, a fuel gas for a polymer electrolyte fuel cell having a reduced amount can be provided.

(2) In the case of the conventional CuO / ZnO catalyst, it is necessary to perform an activation treatment (reduction treatment) of the catalyst before performing the methanol reforming reaction. Since the methanol reforming catalyst according to the present invention does not require an activation treatment step, the operation of transporting the catalyst or the operation of charging the catalyst can be simplified, and the hydrogen production apparatus mounted on a mobile body such as an automobile Easy to use as a catalyst.

In the methanol reforming catalyst according to the present invention, the content of the Pd component is 0.1 to 1 in terms of Pd element.
By setting the content within the range of 0% by weight, the steam reforming reaction activity can be increased, so that the methanol conversion rate can be further improved and the CO concentration of the product gas containing hydrogen as a main component can be reduced. can do.

In the methanol reforming catalyst according to the present invention, the active species may be an alloy containing Pd and Pt,
Alternatively, by using an alloy containing Pd and Cu, a CO shift reaction (CO + H ₂ O → CO ₂ +
Since the H ₂ ) activity can be increased, the CO concentration of the product gas containing hydrogen as a main component can be further reduced.

According to the present invention, a methanol reforming catalyst having a methanol steam reforming reaction activity and CH ₃ OH and H ₂
Both the raw material gas containing O warmed in methanol reforming method of generating of H ₂ containing gas from the raw material gas by the methanol reforming catalyst, as the methanol reforming catalyst, or amphoteric oxides, or amphoteric By using a carrier comprising a composite oxide of an oxide and an active species supported on the carrier and containing a Pd component,
The conversion of methanol when the methanol reforming reaction is performed at a high temperature of 300 ° C. or higher can be improved, and the CO concentration in the generated hydrogen-containing gas can be reduced. Therefore, when the reforming method according to the present invention is applied to the production of a fuel gas for a polymer electrolyte fuel cell, a high-quality fuel gas having a low CO concentration can be obtained.

Further, according to the present invention, CH ₃ OH, H ₂ O
A methanol reforming catalyst is used to generate a methanol steam reforming reaction in the raw material gas containing oxygen and O _2, and a methanol oxidation reaction is caused as a side reaction, and the heat of formation of the oxidation reaction is used as the reaction heat of the steam reforming reaction. in methanol reforming method of generating of H ₂ containing gas from the raw material gas by, as the methanol reforming catalyst,
By using a carrier comprising an amphoteric oxide or a complex oxide of an amphoteric oxide and an active species supported on the carrier and containing a Pd component, a methanol reforming reaction at a high temperature of 300 ° C. or more is performed. Can be improved, and the CO concentration in the generated hydrogen-containing gas can be reduced. In addition, since the heat generated by the methanol oxidation reaction is used as the reaction heat of the steam reforming reaction, the energy efficiency of the methanol reforming reaction can be increased. Therefore, if the reforming method according to the present invention is applied to the generation of a fuel gas for a polymer electrolyte fuel cell, a high-quality fuel gas having a low CO concentration can be produced with high energy efficiency.

In the methanol reforming method according to the present invention, by maintaining the temperature of the methanol reforming catalyst at 300 to 500 ° C., the steam reforming reaction activity of the catalyst can be further increased. Further, the concentration can be further improved, and the CO concentration of the product gas containing hydrogen as a main component can be further reduced.

[0034]

Embodiments of the present invention will be described below in detail.

Example 1 Preparation of Catalyst 1 Zinc hydroxide (Zn (OH) ₂ or Z
nO.H ₂ O) powder at 500 ° C. for 3 hours in an air atmosphere;
Powder A was obtained by firing at atmospheric pressure. 24.25
g of powder A was mixed with about 30 cc of distilled water to prepare slurry B. The obtained slurry B was mixed well with a slurry C obtained by adding an aqueous solution of palladium nitrate (Pd (NO ₃ ) ₂ aq) to an amount of 0.75 g of Pd, and evaporated to dryness on a hot plate at about 200 ° C. Powder D was obtained. Powder D obtained
Is fired at 500 ° C. for 3 hours under atmospheric pressure in the atmosphere, and the composition is PdO / ZnO (the active species is PdO and the carrier is Zn
O) The methanol steam reforming catalyst 1 represented by O) was obtained.

[Preparation of Catalyst 2] Table 1 below shows a procedure similar to that of Catalyst 1 described above, except that Ce ₂ (CO ₃ ) ₃ was used instead of zinc hydroxide in the preparation of powder A. A methanol steam reforming catalyst 2 having a composition was obtained.

[Preparation of Catalyst 3] The composition shown in Table 1 below was prepared by the same procedure as that of Catalyst 1 described above except that Ce (OH) ₄ was used instead of zinc hydroxide in the preparation of powder A. Thus, a methanol steam reforming catalyst 3 was obtained.

[Preparation of Catalyst 4] A composition shown in Table 1 below was prepared by the same procedure as that of Catalyst 1 except that Ce (NO ₃ ) ₃ was used instead of zinc hydroxide in the preparation of powder A. Was obtained.

[Preparation of Catalyst 5] Methanol having the composition shown in Table 1 below was prepared by the same procedure as that of Catalyst 1 described above, except that tin oxalate was used instead of zinc hydroxide in the preparation of powder A. A steam reforming catalyst 5 was obtained.

[Preparation of Catalyst 6] Methanol steam having the composition shown in Table 1 below was prepared by the same procedure as in Catalyst 1 described above, except that tin chloride was used instead of zinc hydroxide in the preparation of powder A. A reforming catalyst 6 was obtained.

[Preparation of Catalyst 7] Methanol having a composition shown in Table 1 below was prepared by the same procedure as that of Catalyst 1 except that titanium ethoxide was used instead of zinc hydroxide in the preparation of powder A. A steam reforming catalyst 7 was obtained.

[Preparation of Catalyst 8] Methanol steam having the composition shown in Table 1 below was prepared by the same procedure as that of Catalyst 1 described above, except that titanium chloride was used instead of zinc hydroxide in the preparation of powder A. A reforming catalyst 8 was obtained.

[Preparation of Catalyst 9] Methanol having a composition shown in Table 1 below was prepared by the same procedure as that of Catalyst 1 except that aluminum hydroxide was used instead of zinc hydroxide in the preparation of powder A. A steam reforming catalyst 9 was obtained.

[Preparation of Catalyst 10] Methanol steam having the composition shown in Table 1 below was prepared by the same procedure as that of Catalyst 1 described above, except that aluminum chloride was used instead of zinc hydroxide in the preparation of powder A. A reforming catalyst 10 was obtained.

[Preparation of Catalyst 11] Methanol having the composition shown in Table 1 below was prepared by the same procedure as in Catalyst 1 described above, except that zirconium hydroxide was used instead of zinc hydroxide in the preparation of powder A. A steam reforming catalyst 11 was obtained.

The content of PdO in each of the catalysts 1 to 11 is PdO
It was 3% by weight in terms of element.

(Example 2) [Preparation of catalyst 12] Zinc hydroxide powder was placed in an air atmosphere for 50 minutes.
Powder A is obtained by baking at 0 ° C. for 3 hours at atmospheric pressure
Was. Mix 24.25 g of powder A with about 30 cc of distilled water
Then, a slurry B was prepared. Nitric acid is added to the obtained slurry B.
Palladium aqueous solution (Pd (NO_Three)_Twoaq) when Pd is 0.
375 g and dinitroxiammine platinum (Pt)
(NH _Three)_Two(NO_Two)_Twoaq) Pt becomes 0.375 g
And the slurry C to which about 200 ° C.
Evaporate to dryness on a hot plate to obtain Powder D. Obtained
Baking powder D in air at 500 ° C for 3 hours at atmospheric pressure
And the composition is Pd-Pt / ZnO (active species are Pd and Pt
An alloy consisting of: wherein the support is methanol represented by ZnO)
A steam reforming catalyst 12 was obtained.

[Preparation of Catalyst 13] Except for using Ce ₂ (CO ₃ ) ₃ in place of zinc hydroxide in the preparation of powder A, the procedure is the same as that of catalyst 12 described above, and is shown in Table 1 below. A methanol steam reforming catalyst 13 having a composition was obtained.

[Preparation of Catalyst 14] Except for using Ce (OH) ₄ instead of zinc hydroxide in the preparation of powder A, the composition shown in Table 1 below was obtained by the same procedure as for catalyst 12 described above. Thus, a methanol steam reforming catalyst 14 was obtained.

[Preparation of Catalyst 15] The composition shown in the following Table 1 was prepared by the same procedure as that for the above-mentioned catalyst 12, except that Ce (NO ₃ ) ₃ was used instead of zinc hydroxide in the preparation of powder A. Was obtained.

[Preparation of Catalyst 16] Except for using tin oxalate instead of zinc hydroxide in the preparation of powder A,
A methanol steam reforming catalyst 16 having a composition shown in Table 1 below was obtained by the same procedure as that for the catalyst 12 described above.

[Preparation of Catalyst 17] Methanol steam having the composition shown in Table 1 below was prepared by the same procedure as that for Catalyst 12 described above, except that tin chloride was used instead of zinc hydroxide in the preparation of powder A. A reforming catalyst 17 was obtained.

[Preparation of Catalyst 18] Methanol having the composition shown in Table 1 below was prepared by the same procedure as that of Catalyst 12 described above, except that titanium ethoxide was used instead of zinc hydroxide in the preparation of powder A. A steam reforming catalyst 18 was obtained.

[Preparation of Catalyst 19] Except for using titanium chloride instead of zinc hydroxide in the preparation of powder A,
A methanol steam reforming catalyst 19 having a composition shown in Table 1 below was obtained by the same procedure as that for the catalyst 12 described above.

[Preparation of Catalyst 20] Except that aluminum hydroxide was used in place of zinc hydroxide in the preparation of powder A, the same procedure as for catalyst 12 described above was used, as shown in Table 1 below.
Methanol steam reforming catalyst 20 having a composition represented by the formula:
I got

[Preparation of Catalyst 21] Except for using aluminum chloride instead of zinc hydroxide in the preparation of powder A, methanol steam having the composition shown in Table 1 below was prepared in the same procedure as for catalyst 12 described above. A reforming catalyst 21 was obtained.

[Preparation of Catalyst 22] Except that zirconium hydroxide was used in place of zinc hydroxide in the preparation of powder A, the same procedure as for catalyst 12 described above was used, as shown in Table 1 below.
Methanol steam reforming catalyst 22 having a composition represented by
I got

The content of Pd contained in the Pd component in each of the obtained catalysts 12 to 22 was 1.5% by weight.

Example 3 Zinc hydroxide powder and cerium carbonate (Ce ₂ (CO ₃ ) ₃ ) were mixed at a molar ratio of Zn to Ce of 1: 1.
Powder mixed at 500 ° C under air atmosphere
The powder A was obtained by firing at atmospheric pressure for a time. 2
4.25 g of powder A was mixed with about 30 cc of distilled water to prepare slurry B. To the obtained slurry B, a slurry C obtained by adding an aqueous solution of palladium nitrate to a Pd amount of 0.75 g was mixed well and evaporated to dryness on a hot plate at about 200 ° C. to obtain a powder D. The obtained powder D is fired at 500 ° C. for 3 hours under atmospheric pressure in the atmosphere, and the composition is PdO / Z.
nO-CeO ₂ (active species is PdO, carriers are ZnO and C
Thus, a methanol steam reforming catalyst 23 represented by a composite oxide of eO ₂ ) was obtained.

The PdO content of the obtained catalyst 23 was P
It was 3% by weight in terms of d element.

(Comparative Example) [Preparation of Comparative Catalyst 1] 19.4 g of γ-alumina was mixed with about 30 cc of distilled water to prepare a slurry. An aqueous solution of dinitrodiammineplatinum was added to the obtained slurry at a Pt of 0.6.
g, mixed well, and evaporated to dryness on a hot plate at about 200 ° C. to obtain a powder. The obtained powder was calcined under atmospheric pressure at 500 ° C. for 3 hours under atmospheric pressure to obtain Comparative Catalyst 1 having a composition shown in Table 1 below.

[Preparation of Comparative Catalyst 2] A powder was obtained by calcining zinc hydroxide powder at 500 ° C. for 3 hours under atmospheric pressure in the air atmosphere. 20 g of the obtained powder is distilled water about 30 c.
c and a slurry was prepared. The resulting slurry was mixed with an aqueous solution of copper nitrate in an amount of 10 g as Cu and mixed and evaporated to dryness on a hot plate at about 200 ° C. to obtain a powder. The obtained powder was calcined at 300 ° C. for 3 hours under atmospheric pressure in the atmosphere to obtain Comparative Catalyst 2 having the composition shown in Table 1 below.

The obtained methanol reforming catalysts 1 to 23 and comparative catalysts 1 and 2 were subjected to a methanol reforming reaction under the conditions shown in the following Tables 2 and 3 by a flow-through microreactor, and the catalytic performance (methanol conversion rate and C at reactor outlet
O concentration) is shown in Table 1 below. In the methanol reforming reaction shown in Table 2, a mixed gas consisting of methanol and steam was used as a raw material gas, and the average temperature of the catalyst was maintained at 300 ° C. by heating the reactor with a heater. On the other hand, in the methanol reforming reaction shown in Table 3, a mixed gas consisting of methanol, steam and air was used as a raw material gas, and the average temperature of the catalyst was kept at 300 ° C. by heat generated by a partial oxidation reaction of methanol. In each of the methods shown in Tables 2 and 3, Comparative Catalyst 2
Was subjected to a reduction treatment before the steam reforming reaction.

The conversion rate of methanol, which is an evaluation parameter, was calculated based on the following definition equation (1) by analyzing the composition of the reaction gas using a TCD and FID detector type gas chromatograph.

Methanol conversion (%) = (1−X / Y) × 100 (1) where, in the formula (1), X is a methanol flow rate (mol / h) at a reactor outlet, and Y is a reactor inlet. Shows the methanol flow rate (mol / h).

[0066]

[Table 1]

[0067]

[Table 2]

[0068]

[Table 3]

As is clear from Table 1, the catalyst of Example 1 containing a carrier comprising an amphoteric oxide or a complex oxide of an amphoteric oxide and an active species containing a Pd component carried on the carrier.
No. 23 to No. 23 indicate that the comparative catalyst 1 having the active species of Pt and the composition thereof have the same composition in either the case where the reaction heat of the steam reforming reaction is supplied from the outside or the case where the heat generated by the partial oxidation reaction of methanol is used. It can be seen that, as compared to the comparative catalyst 2 represented by CuO / ZnO, the methanol conversion rate can be increased, and the CO concentration of the product gas containing hydrogen as a main component can be reduced.

Further, the catalysts of Examples 1 to 11 and 23 of the Example catalyst were activated P during the methanol reforming reaction.
dO changed to Pd, and the active species after the completion of the methanol reforming reaction consisted only of Pd.

[0071]

As described in detail above, according to the present invention, the heat resistance of the catalyst is improved, and when the steam reforming reaction of methanol is performed at a high temperature of 300 ° C. or more, the methanol is removed at a high temperature of 300 ° C. or more. Methanol reforming catalyst and methanol reforming that improve the methanol conversion rate during the steam reforming reaction and methanol oxidation reaction, and have a low CO concentration in the generated hydrogen-containing gas, and furthermore do not require an activation treatment step. A method can be provided.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C01B 3/32 H01M 8/06 A H01M 8/06 8/10 // H01M 8/10 B01J 23/56 301M (72) Inventor Shigeru Nojima 4--22 Kannon Shinmachi, Nishi-ku, Hiroshima City, Hiroshima Prefecture Inside the Hiroshima Research Laboratory, Mitsubishi Heavy Industries, Ltd. F-term in Hiroshima R & D Co., Ltd. (Reference) 4G040 EA02 EA06 EA07 EC01 EC03 EC04 4G069 AA03 BA01A BA01B BA04A BA04B BB02A BB02B BB04A BB04B BB06A BB06B BC22A BC22B BC31A BC31B BC35A BC35A 5BC BCA BC6A BCBC BC BC

Claims (7)

[Claims] 1. A methanol steam reforming reaction (CH ₃ OH)
+ H ₂ O → CO ₂ + 3H ₂ ) A methanol reforming catalyst having an activity, comprising a carrier comprising an amphoteric oxide or a composite oxide of an amphoteric oxide; and an active species supported on the carrier and containing a Pd component. And a methanol reforming catalyst comprising: 2. A methanol steam reforming reaction (CH ₃ OH)
+ H ₂ O → CO ₂ + 3H ₂ ) A methanol reforming catalyst having an activity and causing an oxidation reaction of methanol as a side reaction, comprising a carrier comprising an amphoteric oxide or a composite oxide of an amphoteric oxide; A methanol reforming catalyst supported on the carrier and containing an active species containing a Pd component. 3. The methanol reforming catalyst according to claim 1, wherein the content of the Pd component is within a range of 0.1 to 10% by weight in terms of a Pd element. 4. The method according to claim 1, wherein the active species comprises an alloy containing at least one element selected from Pd and PdO, or at least one element selected from Pt and Cu, and Pd. 3. The methanol reforming catalyst according to any one of claims 1 to 2. 5. A methanol steam reforming reaction (CH ₃ OH)
+ H ₂ O → CO ₂ + 3H ₂ ) Both the methanol reforming catalyst having the activity and the raw material gas containing CH ₃ OH and H ₂ O are heated, and the H ₂ containing gas is removed from the raw material gas by the methanol reforming catalyst. Wherein the methanol reforming catalyst comprises a support made of an amphoteric oxide or a composite oxide of an amphoteric oxide, and an active species supported on the support and containing a Pd component. A method for reforming methanol, characterized in that: 6. CH_ThreeOH, H_TwoO and O_TwoIngredients containing
Steam reforming with methanol reforming catalyst
Yes (CH_ThreeOH + H_TwoO → CO_Two+ 3H_Two)
In both cases, a methanol oxidation reaction occurs as a side reaction,
The heat of formation of the oxidation reaction is used as the heat of reaction of the steam reforming reaction.
To remove H from the source gas. _TwoGenerate contained gas
Wherein the methanol reforming catalyst is an amphoteric oxide or
And a carrier comprising a composite oxide of a conductive oxide and the carrier
And an active species containing a Pd component.
Methanol reforming method. 7. The temperature of the methanol reforming catalyst is 30.
The methanol reforming method according to any one of claims 5 to 6, wherein the temperature is maintained within a range of 0 to 500 ° C.