JPH0568883A - Amorphous alloy catalyst for carbon dioxide conversion - Google Patents

Abstract

PURPOSE:To offer a highly active catalyst used for conversing carbon dioxide to a hydrocarbon having long carbon chains. CONSTITUTION:This carbon dioxide conversion catalyst is formed by oxidation- reduction treating an amorphous alloy consisting of 6-12 atomic % Zr and substantially residual Fe. This catalyst, regardless of the composition with low price meters, shows extremely high catalystic activity by oxidation-reduction treatment, accordingly carbon dioxide is converted at a low temp. to produce hydrocarbon having long carbon chains.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a material having a very simple production method as a highly active catalyst for converting carbon dioxide into a hydrocarbon having a long carbon chain.

[0002]

2. Description of the Related Art A catalyst in which hydrogen is added to carbon monoxide to convert it into a hydrocarbon and water has been extensively studied, and a catalyst in which ruthenium is supported on alumina is known.

By the way, normally, an alloy is crystallized in a solid state, but a method that does not form long-period regularity in an atomic arrangement in the process of solid formation is applied, such as limiting the alloy composition and solidifying from a molten state by rapid quenching. Then, an amorphous structure similar to a liquid is obtained without a crystal structure, and such an alloy is called an amorphous alloy. Amorphous alloys are mostly single-phase alloys with a supersaturated solid solution and have a remarkably high strength as compared with conventional practical metals, and exhibit various characteristics such as abnormally high corrosion resistance depending on the composition.

Amorphous Ni-Zr and Pd-
It is known that the Zr alloy operates as a catalyst for adding hydrogen to carbon monoxide to convert it into hydrocarbon and water even at 250 to 300 ° C., and its activity is several times higher than that of the above-mentioned alumina-supported ruthenium catalyst. On the other hand, no definitive catalyst has been obtained as an effective catalyst for the reaction based on the principle that hydrogen is added to carbon dioxide to change it to hydrocarbon and water.

On the other hand, one of the inventors of the present invention is Japanese Patent Application No. 60-123.
No. 111 filed an application for an amorphous alloy electrode material containing Ni-Ta-platinum group metal as an essential component as an electrode material for oxygen gas generation in aqueous solution electrolysis. Japanese Patent Application Sho 60-12
No. 3111 is as follows.

(1) Ta, Ru, Rh, Pd, Ir,
Pt consisting of one or more elements selected from Group I and the balance substantially Ni, and Ta is 25
~ 65 atom%, the element selected from the group I is 0.3 ~
An electrode for electrolysis, wherein an amorphous alloy having a composition of 45 atomic% and Ni of 30 atomic% or more is immersed in an aqueous solution of hydrofluoric acid to improve the electrode activity.

(2) Ta, Ru, Rh, Pd, Ir,
One or more elements selected from Group I of Pt, one or more elements selected from Group II of Ti, Zr, and Nb, and the balance being substantially And Ni, the Ta is 20 atomic% or more, the element selected from the group I is 0.3 to 45 atomic%, and the Ni has a composition of 30 atomic% or more. An electrode for electrolysis, wherein a crystalline alloy is immersed in an aqueous solution of hydrofluoric acid to improve the electrode activity.

Further, three of the inventors of the present invention are made up of Ti, Zr and N.
A surface-activated amorphous alloy for a solution electrolysis electrode containing one or more of b and Ta and Ni and a platinum group metal, and a method of activating the same are disclosed in Japanese Patent Application No. 60-1.
69764, 60-169765 and 60-16
9767, and likewise, a surface activated supersaturated solid solution alloy for electrodes for solution electrolysis and an activation treatment method thereof were applied as Japanese Patent Application No. 60-169766.

Japanese Patent Application No. 60-169764 comprises the following five inventions.

(1) Nb of 25 to 65 atomic% and Ru, R
0.01 to 10 atomic% of one or more elements selected from the group consisting of h, Pd, Ir, and Pt, and the balance being a solution electrolyzed surface-treated substantially consisting of Ni. Surface activated amorphous alloy for electrolysis.

(2) A total of 25 to 65 atomic% of one or more selected from the group of three metals of Ti, Zr and Ta of less than 20 atomic% and Nb of 10 atomic% or more.
In addition, 0.01 to 10 atomic% of one or more elements selected from the group of Ru, Rh, Pd, Ir and Pt is further included, and the balance is a surface activation treatment consisting essentially of Ni. Surface-activated amorphous alloy for electrolysis of applied solution electrolysis.

(3) Nb of 25 to 65 atomic% and Ru, R
A surface activation treatment containing 0.01 to 10 atomic% of one or more elements selected from the group of h, Pd, Ir and Pt and 0.01 to 10 atomic% of P and the balance substantially Ni. Surface-activated amorphous alloy for electrolysis of solution electrolysis.

(4) Ti, Zr, and one or more selected from the group of three kinds of metals with Ta of less than 20 atomic% and a total of 25 to 65 atomic% of Nb of 10 atomic% or more.
In addition, 0.01 to 10 atomic% of one or more elements selected from the group of Ru, Rh, Pd, It and Pt and 7 atomic% or less of P are contained, and the balance is substantially Ni. A surface-activated amorphous alloy for electrolysis in solution electrolysis that has been subjected to surface activation treatment.

(5) The amorphous alloy for electrodes is replaced with Ni, N
Immersion in a corrosive liquid that preferentially dissolves b, Ta, Ti and Zr. A method for activating an amorphous alloy for an electrode, which comprises concentrating a platinum group metal, which is responsible for the electrode activity, on the surface.

Japanese Patent Application No. 60-169765 comprises the following three inventions.

(1) 25-65 atomic% Ta, R
0.01 to 10 atomic% of one or more elements selected from the group of u, Rh, Pd, Ir and Pt, and 7 atomic% or less of P, and substantially 20 atomic% or more of N as the balance.
A surface-activated amorphous alloy for electrodes for solution electrolysis, which has been subjected to a surface activation treatment in which the total amount is 100 atomic%.

(2) Containing 20 atomic% or more of Ta, T
The sum of Ta and one or more elements selected from the group of i, Zr, and Nb is 25 to 65 atomic%, and R
0.01 to 10 atomic% and 7 atomic% of one or more elements selected from the group of u, Rh, Pd, Ir and Pt.
20% by atom or more of N as a substantial balance including the following P
A surface activated amorphous alloy for electrodes of solution electrolysis, which is made of i and is subjected to a surface activation treatment so that the total amount is 100 atomic%.

(3) The amorphous alloy for electrodes is replaced with Ni, N
A method for activating an amorphous alloy for an electrode, which comprises immersing in a corrosive liquid which preferentially dissolves b, Ta, Ti and Zr to concentrate the platinum group metal responsible for the electrode activity on the surface.

Japanese Patent Application No. 60-169767 comprises the following three inventions.

(1) Ta of 5 atomic% or more and less than 20 atomic%
Containing Ta, the sum of Ta and Zr is 25 to 65 atomic%, and Ru, Rh, Pd,
Surface-activated amorphous for electrode of solution electrolysis containing 0.01 to 10 atomic% of one or more elements of Ir and Pt, and the balance being substantially Ni, and subjected to surface activation treatment. alloy.

(2) Ta of 5 atomic% or more and less than 20 atomic%
And one or two kinds of Ti and Zr and Ta have a total content of 25 to 65 atomic%, and Ru, Rh, Pd and I are contained.
Any one or two or more elements of r and Pt.
Surface activity for electrodes of solution electrolysis containing 01 to 10 atom% and 7 atom% or less of P, the balance being substantially 20 atom% or more of Ni, and having been subjected to surface activation treatment to make the total 100 atom% Amorphous alloy. (3) For an electrode, wherein the amorphous alloy for an electrode is immersed in a corrosive solution in which Ni, Ta, Ti and Zr are preferentially dissolved to concentrate the platinum group metal responsible for the electrode activity on the surface. Method for activating amorphous alloy.

Japanese Patent Application No. 60-169766 comprises the following 5 inventions.

(1) One or two of Nb and Ta 2
Ru, Rh, P containing 0 atomic% or more and less than 25 atomic%
For an electrode for solution electrolysis containing 0.01 to 10 atomic% of one or more elements selected from the group of d, Ir and Pt, and the balance being substantially Ni, and subjected to a surface activation treatment. Supersaturated solid solution alloy.

(2) One or two of Nb and Ta 2
Ru, Rh, P containing 0 atomic% or more and less than 25 atomic%
One or two or more elements selected from the group of d, It and Pt are contained in an amount of 0.01 to 10 atomic% and 7 atomic% or less of P, and the balance is substantially Ni, and a surface activation treatment is performed. Supersaturated solid solution alloy for applied solution electrolysis electrodes.

(3) One or two of Nb and Ta 5
At least 20 atomic% and less than 25 atomic% of Ru, Rh, Pd, and I, and the total of one or two of Ti and Zr and one or two of Nb and Ta is at least 20 atomic%.
One or more selected from the group consisting of r and Pt.
A surface-activated supersaturated solid solution alloy for a solution-electrolyzed electrode, which contains 01 to 10 atomic% and the balance is substantially Ni and is surface-activated.

(4) One or two of Nb and Ta 5
At least 20 atomic% and less than 25 atomic% of Ru, Rh, Pd, Ir and Pt, and the total of one or two of Ti and Zr and one or two of Nb and Ta is at least 20 atomic%. 1 type or 2 or more types selected from the group 0.01
A surface-activated supersaturated solid solution alloy for solution electrolysis electrodes, which contains -10 atomic% and 7 atomic% or less P, and the balance is substantially Ni, and which has been surface-activated.

(5) The supersaturated solid solution alloy for the electrode is replaced with N
A method for activating a supersaturated solid solution alloy for an electrode, which comprises immersing i, Nb, Ta, Ti and Zr in a corrosive liquid that preferentially dissolves the platinum group metal, which is responsible for the electrode activity, to concentrate on the surface.

Furthermore, the present inventors have found a surface-activated amorphous alloy for a methanol fuel cell, and have proposed a Japanese Patent Application No. 61-61.
Filed as No. 154570. Japanese Patent Application No. Sho 61-154
No. 570 is as follows.

(1) Pt 0.5 to 20 atomic%, one or two kinds of Ti and Zr 20 to 80 atomic%, and the balance substantially one or two kinds of Ni and Co 10 atomic% or more. A characteristic surface-activated amorphous alloy for methanol-based fuel cell electrodes.

(2) Pt 0.5 to 20 atomic%, one or two kinds of Ti and Zr 20 to 80 atomic%, Ru, R
1 or 2 or more selected from the group consisting of h, Pd, Ir, Tl, Si, Ge, Sn, Pb and Bi and 10 atomic% or less (however, when Pt is 10 atomic% or less, atomic%
And less than the same amount as Pt), and the balance is substantially 1 of Ni and Co.
A surface-activated amorphous alloy for a fuel electrode for a methanol-based fuel cell, characterized in that it is composed of at least 10 atomic% of two kinds or two kinds.

(3) Pt 0.5 to 20 atomic%, one or two kinds of Nb and Ta, 20 to 70 atomic%, and the balance substantially one or two kinds of Ni and Co, methanol. -Activated amorphous alloy for lithium-based fuel cell electrodes.

(4) Pt 0.5 to 20 atomic%, Nb and Ta 1 or 2 kinds 20 to 70 atomic%, Ru, R
1 or 2 or more selected from the group consisting of h, Pd, Ir, Ti, Si, Ge, Sn, Pb and Bi, 10 atomic% or less (however, when Pt is 10 atomic% or less, atomic%
And less than the same amount as Pt), and the balance is substantially 1 of Ni and Co.
A surface-activated amorphous alloy for a fuel electrode for a methanol-based fuel cell, characterized in that it is composed of at least 10 atomic% of two kinds or two kinds.

(5) Pt 0.5 to 20 atomic%, one or two kinds of Nb and Ta of 70 atomic% or less, and Ti and Z
20 to 80 atomic% in total with 1 or 2 kinds of r (including the amount of 1 or 2 kinds of Nb and Ta described above), and the balance substantially 1 atomic or 2 kinds of Ni and Co of 10 atomic% or more A surface-activated amorphous alloy for a methanol-based fuel cell electrode, comprising:

(6) Pt 0.5 to 20 atomic%, Nb and Ta 1 or 2 kinds 70 atomic% or less, and Ti and Z
20 to 80 atomic% in total with 1 or 2 of r (including the amount of 1 or 2 of Nb and Ta described above), Ru,
One or more selected from the group consisting of Rh, Pd, Ir, Tl, Si, Ge, Sn, Pb and Bi 10
Methanol-based, characterized in that it is atomic% or less (however, when Pt is 10 atomic% or less, atomic% is the same as or less than Pt), and the balance substantially consists of one or two kinds of Ni and Co, 10 atomic% or more. Surface activated amorphous alloy for fuel cell electrodes.

Further, three of the inventors of the present invention have found that a catalyst in which a platinum group element is supported on ceramics used for purifying exhaust gas from an apparatus / engine for burning various organic substances has a high operating temperature and is expensive platinum. In order to solve the drawback that it is not easy to recover the group element and regenerate the catalyst, it is necessary to use a catalyst that is easy to recover and operates even at low temperatures that can purify even low temperature exhaust gas at the start of combustion. Conducted research and found an exhaust gas purification catalyst that decomposes and detoxifies carbon monoxide and nitrogen oxides in exhaust gas. Japanese Patent Application No. 1-262.
Filed as No. 986. Japanese Patent Application No. 1-262986 is as follows. (1) One or two kinds of Nb and Ta, 20 to 70 atomic%, one or more kinds of elements selected from the group of Ru, Pd, Rh, Pt and Ir, 0.5 to 20 atomic%, and the balance substantially N.
An exhaust gas purifying catalyst, characterized in that an amorphous alloy of one or two of i and Co is subjected to activation treatment by immersion in hydrofluoric acid.

(2) One or two of Ti and Zr 2
0 to 80 atomic%, one or more elements selected from the group of Ru, Pd, Rh, Pt and Ir 0.5 to 20 atomic%, and the balance substantially one or two kinds of Ni and Co 10 atomic%.
An exhaust gas purifying catalyst, characterized in that the above amorphous alloy is subjected to activation treatment by immersion in hydrofluoric acid. (3) Total amount of one or two kinds of Nb and Ta of 70 atomic% or less and one or two kinds of Ti and Zr, 20 to 8
0 atom% (including the amount of one or two of Nb and Ta described above), 0.5 to 20 atom% of one or more elements selected from the group of Ru, Pd, Rh, Pt and Ir, the balance substantially An exhaust gas purifying catalyst, characterized in that an amorphous alloy consisting of 10 atomic% or more of one or two of Ni and Co is subjected to activation treatment by dipping in hydrofluoric acid.

Further, the inventors of the present invention conducted a research on a catalyst for reacting carbon dioxide with hydrogen at a low temperature to produce a hydrocarbon based on the above-mentioned conventional research results on the amorphous alloy. It was found that a high performance catalyst for conversion of carbon dioxide can be obtained from an amorphous alloy filed as No. 262986.
Filed as No. 60. Japanese Patent Application No. 2-45660 comprises the following three inventions.

(1) One or two of Nb and Ta 2
Amorphous alloy consisting of 0 to 70 atomic%, 0.5 to 20 atomic% of one or more elements selected from the group of Ru, Pd, Rh, Pt and Ir, and the balance substantially consisting of 1 or 2 elements of Ni and Co. A carbon dioxide conversion catalyst, characterized in that the carbon dioxide is subjected to activation treatment by immersion in hydrofluoric acid.

(2) One or two of Ti and Zr 2
0 to 80 atomic%, one or more elements selected from the group of Ru, Pd, Rh, Pt and Ir 0.5 to 20 atomic%, and the balance substantially one or two kinds of Ni and Co 10 atomic%.
A catalyst for carbon dioxide conversion, characterized in that the above amorphous alloy is subjected to activation treatment by immersion in hydrofluoric acid.

(3) One or two of Nb and Ta 7
Total amount of 0 atomic% or less and one or two kinds of Ti and Zr, 20 to 80 atomic% (including the amount of one or two kinds of Nb and Ta described above), Ru, Pd, Rh, Pt and Ir.
0.5 to 20 atomic% of one or more elements selected from the group
A catalyst for carbon dioxide conversion, characterized in that an activation treatment by dipping in hydrofluoric acid is applied to an amorphous alloy consisting essentially of 10% by atom or more of one or two of Ni and Co.

[0041]

The global warming caused by a large amount of carbon dioxide released has become a social problem. However, it is difficult to reduce carbon dioxide emissions while maintaining the current level of industrial activities and the standard of living. Therefore, a facility must be developed to return the carbon dioxide released to hydrocarbons for reuse without the need for large amounts of energy. For this purpose, the advent of a highly active and easily regenerated catalyst capable of carrying out a reaction of converting carbon dioxide into a hydrocarbon at a low energy consumption is awaited.

[0042]

The present invention provides a highly active catalyst capable of carrying out the reaction of reacting carbon dioxide with hydrogen to convert it to a hydrocarbon having a long carbon chain even at a temperature close to room temperature. is there. The inventors of the present invention have conducted research on a catalyst for producing a hydrocarbon by reacting carbon dioxide with hydrogen at a low temperature based on the above-mentioned conventional research results on an amorphous alloy, and a hydrocarbon having a long carbon chain such as C ₂ and C _3. As a result of a study focusing on a catalyst that produces, a high-performance catalyst was obtained by finding that a high-performance catalyst can be obtained by subjecting an amorphous alloy containing iron as a main component and containing zirconium to a redox treatment.

The present invention provides a highly active catalyst obtained by subjecting an amorphous alloy containing Fe as a main component and a small amount of Zr necessary for forming an amorphous structure to a redox treatment.

These are amorphous alloys composed of 6 to 12 atomic% Zr and the balance substantially Fe.

[0045]

[Function] In order to obtain a catalyst that has a high selective catalytic activity for a specific chemical reaction and is easy to produce and regenerate, it is preferable to use an active element rather than loading a platinum group element on alumina, titania, silica, or the like. It is more convenient to use the alloy containing the required amount. However, in the case of a crystalline metal produced by a usual method, addition of a large amount of various alloying elements often results in a multiphase structure having different chemical properties, and it is not possible to have predetermined properties. Moreover, since it is brittle, it is difficult to obtain a material having a large specific surface area required as a catalyst.

On the other hand, in the amorphous alloy of the present invention obtained by ultra-quenching a molten alloy having the above composition, it is necessary to form a solid phase rapidly so that constituent elements are not localized. Therefore, it has excellent mechanical properties such as strength and toughness while uniformly dissolving the predetermined element in solid solution. When this is subjected to an oxidation treatment, both iron and zirconium are oxidized, but when subjected to a reduction treatment, only iron is reduced, and carbon chains such as C ₂ and C ₃ that have fine iron supported on zirconium oxide are supported. A highly active catalyst is obtained which produces long hydrocarbons. In this case, since the amorphous alloy is a uniform solid solution, iron is uniformly distributed on zirconium oxide, and a highly active catalyst composed of fine iron is obtained, which is effective for producing hydrocarbons with long carbon chains as the surface area increases. Be done.

That is, a catalyst that can act even at low temperature as an amorphous alloy catalyst that produces hydrogen having a long carbon chain such as C ₂ and C ₃ by acting hydrogen on carbon dioxide is subjected to redox treatment on the alloy having the above composition. It is realized by the catalyst of the present invention.

Next, the reasons for limiting the component composition in the present invention will be described.

In the case of an alloy with Fe which has the catalytic effect of the present invention, an amorphous structure can be easily obtained when Zr is 6 to 12 atom%. When this is subjected to redox treatment, a catalyst in which Fe is finely dispersed on zirconium oxide is obtained. If Zr is more than this range, not only an amorphous alloy cannot be obtained, but also finely dispersed Fe.
The amount of is small, and high catalytic activity cannot be obtained. Also, Zr
If it is too small, not only an amorphous alloy cannot be obtained, but also zirconium oxide is insufficient and Fe is not finely dispersed, so that high activity cannot be obtained.

For the production of the amorphous alloy of the present invention, a method which is widely used and which is used to form an amorphous alloy by rapidly quenching and solidifying a liquid alloy is used.

As an example, an apparatus for producing the amorphous alloy of the present invention is shown in FIG. The part surrounded by the dotted line is filled with an inert gas after being evacuated. In the figure, 2 is a quartz tube having a vertical nozzle 3 at its lower end, and a raw material 4 and an inert gas for preventing the raw material from being oxidized can be fed from an inlet 1 provided at the upper end of the quartz tube 2. it can.
A heating furnace 5 is installed around the quartz tube 2 to heat the sample 4. A high-speed rotation roll 7 is placed vertically below the nozzle 3 and rotated by a motor 6.

In order to produce an amorphous alloy, a raw material 4 having a predetermined composition is put in a quartz tube 2 and the apparatus is first set to 10 ^-5 To.
After applying a vacuum of about rr, an inert gas is filled. Next, the raw material 4 is heated and melted by the heating furnace 5, and the molten metal is heated by the motor 6 at 1,000 to 10,000 rpm p. m.
The pressurized inert gas is sprayed onto the outer peripheral surface of the roll 7 which is rotating at high speed. By this method, the amorphous alloy of the present invention can be obtained as a long thin plate having a thickness of 0.1 mm, a width of 10 mm, and a length of several meters.

[0053]

【Example】

Example 1 Raw material metals were mixed so as to have a composition of Fe-9 atomic% Zr, and a raw material alloy was produced by argon arc melting. This alloy is remelted in an argon atmosphere and is rapidly quenched and solidified using the single roll method shown in FIG. 1 to obtain a thickness of 0.01 to 0.05 mm, a width of 1 to 3 mm, and a length of 3 to 20.
An amorphous alloy thin plate of m was obtained. The formation of the amorphous structure was confirmed by X-ray diffraction. This alloy sample was oxidized in an oxygen atmosphere at 500 ° C. for 3 hours and then reduced in a hydrogen atmosphere at 300 ° C. for 1 hour to obtain a metallic highly active catalyst.
0.5 g of the catalyst thus obtained was packed in a glass tube having an inner diameter of 8 mm to a length of 5 cm to form a reaction tube, which was placed in an electric furnace. A gas containing CO ₂ and H ₂ in a molecular ratio of 1: 4 was passed through the reaction tube at a flow rate of 15 ml / min, and CO
_The amounts of ₂ , CH ₄ , C ₂ H ₄ , C ₂ H ₆ and C ₃ H ₈ were measured by gas chromatography. The reaction amount is as follows.

Reaction temperature Weight of hydrocarbon produced in 1 h per 1 g of amorphous alloy catalyst mg CH ₄ C ₂ H ₄ C ₂ H ₆ C ₃ H ₈ 200 0.2 − − − 250 4.5 − 0.3 0. 1 300 37.7 3.1 5.0 2.7 Example 2 Raw material metals were mixed so as to have a composition of Fe-7 atomic% Zr, and a raw material alloy was produced by argon arc melting. This alloy is remelted in an argon atmosphere and is rapidly quenched and solidified using the single roll method shown in FIG. 1 to give a thickness of 0.01 to 0.05 mm, a width of 3 mm, and a length of 3 to 20 m.
The amorphous alloy thin plate of was obtained. The formation of the amorphous structure was confirmed by X-ray diffraction. This alloy sample was oxidized in an oxygen atmosphere at 500 ° C. for 3 hours and then in a hydrogen atmosphere for 30 hours.
Reduction was carried out at 0 ° C. for 1 hour to obtain a metallic high activity catalyst. 0.5 g of the catalyst thus obtained was added to 5 c in a glass tube having an inner diameter of 8 mm.
The reaction tube was packed into a length of m and installed in an electric furnace. A gas containing CO ₂ and H ₂ at a molecular ratio of 1: 4 was flown into the reaction tube at a flow rate of 1
Flowing at 5 ml / min, CO ₂ , C at the outlet of the reaction tube
The amounts of H ₄ , C ₂ H ₄ , C ₂ H ₆ and C ₃ H ₈ were measured by gas chromatography. The reaction amount is as follows.

Reaction temperature Weight of hydrocarbon formed in 1 h per 1 g of amorphous alloy catalyst CH ₄ C ₂ H ₄ C ₂ H ₆ C ₃ H ₈ 200 − − − − 250 2.1 − − − 300 27.6 − 3.7 1.8 Example 3 Raw material metals were mixed so as to have a composition of Fe-11 atomic% Zr, and a raw material alloy was produced by argon arc melting.
This alloy is remelted in an argon atmosphere and is rapidly quenched and solidified using the single roll method shown in FIG. 1 to obtain a thickness of 0.01 to 0.05 mm, a width of 1 to 3 mm, and a length of 3 to 20.
An amorphous alloy thin plate of m was obtained. The formation of the amorphous structure was confirmed by X-ray diffraction. This alloy sample was oxidized in an oxygen atmosphere at 500 ° C. for 3 hours and then reduced in a hydrogen atmosphere at 300 ° C. for 1 hour to obtain a metallic high activity catalyst. 0.5 g of the catalyst thus obtained was packed in a glass tube having an inner diameter of 8 mm to a length of 5 cm to form a reaction tube, which was placed in an electric furnace. A gas containing CO ₂ and H ₂ in a molecular ratio of 1: 4 was passed through the reaction tube at a flow rate of 15 ml / min, and CO
_The amounts of ₂ , CH ₄ , C ₂ H ₄ , C ₂ H ₆ and C ₃ H ₈ were measured by gas chromatography. The reaction amount is as follows.

Reaction temperature Weight of hydrocarbon produced in 1 h per 1 g of amorphous alloy catalyst mg CH ₄ C ₂ H ₄ C ₂ H ₆ C ₃ H ₈ 200 0.1 − − − 250 3.0 − 0.1 0. 1 300 14.3-1.3 0.6 As described above, in all of the amorphous alloy catalysts for carbon dioxide conversion of the present invention, carbon dioxide is reacted with hydrogen at an extremely low temperature to convert it into a hydrocarbon having a long carbon chain. It was revealed that it was able to do so and had a remarkably high activity.

[0057]

As described above, the amorphous alloy of the present invention exhibits an extremely high catalytic activity by being subjected to a redox treatment, even though it is made of an inexpensive metal, so that carbon dioxide can be heated at a low temperature. It has a remarkably high catalytic activity that can be converted into a hydrocarbon having a long carbon chain.

Further, the highly active catalyst of the present invention is obtained by subjecting a ribbon-shaped amorphous alloy produced by a liquid quenching method including a single roll method generally used for producing an amorphous alloy to a redox treatment. , Does not require special equipment.

Therefore, the preparation of the high activity catalyst of the present invention does not require particularly complicated and expensive operations, and the high activity catalyst of the present invention thus produced has excellent catalytic activity and is excellent in practicality. ..

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an example of an apparatus for producing an alloy of the present invention.

[Explanation of symbols]

 1 Inlet 2 Quartz Tube 3 Vertical Nozzle 4 Raw Material 5 Heating Furnace 6 Motor 7 High Speed Rotating Roll

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Asahi Kawashima 37-17 Hiyoridai, Taihaku-ku, Sendai City, Miyagi Prefecture

Claims (1)

[Claims] 1. Zr of 6-12 atomic% and the balance substantially F
A catalyst for carbon dioxide conversion, which is obtained by subjecting an amorphous alloy of e to a redox treatment.