JP2004267878A - Heat-resistant catalyst prepared by using quasi-crystal aluminum alloy as precursor and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a copper-based catalyst having high activity and excellent heat resistance and durability and a method for preparing this catalyst at a low cost by using a process as simple as possible. <P>SOLUTION: This heat-resistant catalyst is composed of composite particles prepared by sticking Cu nanoparticles and Co nanoparticles uniformly dispersedly to the surface of a particle of a quasi-crystal Al alloy obtained by crushing and leaching an ingot of the quasi-crystal Al alloy having the composition shown by the general formula: Al<SB>100-a-b-c</SB>Cu<SB>a</SB>Co<SB>b</SB>(wherein 5 atom%≤a≤30 atom%; 5 atom%≤b≤25 atom%). When this catalyst is made to be a quaternary alloy by adding Fe of ≤10 atom%, a quasi-crystal can be formed in a wider composition range and the catalytic activity can be made higher. The catalytic activity of this catalyst can be made high linearly even at 400°C. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention provides a composite particle obtained by using a quasicrystalline Al alloy as a precursor and having high activity, excellent heat resistance, and excellent durability, in which Cu nanoparticles and Co nanoparticles are uniformly dispersed and fixed on the surfaces of quasicrystalline Al alloy particles. And a method for producing the same.
[0002]
[Prior art]
Copper-based catalysts are widely used for steam reforming of methanol, methanol synthesis, water gas shift reaction, hydrogenation and hydrocracking of organic compounds, and the like. However, in general, copper-based catalysts have very low heat resistance and durability, so that use conditions and the like are often limited.
[0003]
For example, in recent years, the need for hydrogen energy has been increasing from the viewpoint of environmental problems such as global warming due to an increase in CO ₂ emissions. However, hydrogen is a gas and therefore difficult to store. When used as a fuel for mobile objects such as automobiles, it is desirable to generate a necessary amount of hydrogen when used. Of these methods, the steam reforming reaction of methanol is the most effective method. Methanol is easily reformed into a gas having a high hydrogen concentration by steam reforming represented by the following reaction formula (1) in the presence of a catalyst and steam.
[0004]
CH ₃ OH + H ₂ O → 3H ₂ + CO ₂ (1)
[0005]
This steam reforming reaction of methanol is characterized in that hydrogen can be obtained more efficiently at a lower temperature than the steam reforming reaction of hydrocarbons such as natural gas and PLG, and that there are few by-products such as CO. In particular, Takezawa et al. Have already reported that a copper-based catalyst exhibits high selectivity in a steam reforming reaction of methanol (Non-Patent Document 1).
[0006]
However, when hydrogen is used in power generation, cogeneration or on-board fuel cells, the performance of current copper-based catalysts is insufficient, and high durability and high activity and high selectivity are maintained even at high temperatures. There is a demand for a catalyst having good properties. Conventionally, as a method for producing this type of copper-based catalyst, there has been known a method for producing a catalyst composed of a copper / zinc-based oxide by a kneading method or a coprecipitation method (for example, Patent Documents 1 and 2).
[0007]
In addition, a Raney-type methanol synthesis catalyst that develops a binary or ternary alloy with an aqueous solution of an alkali metal hydroxide is also known (Patent Documents 3 to 6). The amorphous alloy ribbon-shaped catalyst material produced by rapid solidification is decomposed into powder by elution treatment with acid or alkali, and its surface layer is a mixed phase of Cu-based ultrafine particles and ultrafine particles of rare earth elements, transition metals, precious metals, etc. A method for producing a certain methanol steam reforming catalyst (Patent Document 7) and the like are also being studied. It is also known that ultrafine particles of a quasicrystalline Al alloy composed of Al and Cu, Ni, Pd, etc. have high activity in a methanol decomposition reaction (Patent Document 8). In addition, a catalyst comprising composite ultrafine particles obtained by heating and dissolving and evaporating a raw material composed of aluminum and a metal element has been considered (Patent Document 9).
[0008]
Further, the present inventors pulverize an Al alloy ingot composed of a quasicrystal containing Al and at least one kind of metal atom selected from Cu, Fe, Ru, and Os, and hydrolyze the obtained alloy particles. A method for producing a methanol steam reforming catalyst characterized by etching with a sodium aqueous solution was developed (Patent Document 10, Non-Patent Documents 2, 3, and 4). Also, a methanol steam reforming catalyst comprising an alloy containing copper, zinc, palladium and / or platinum is known (Patent Document 11).
[0009]
[Non-patent document 1]
Catalyst, vol. 37 (1995) 320
[Non-patent document 2]
Applied catalyst A: General 214 (2001) 237-241.
[Non-Patent Document 3]
Journal of Alloys and Compounds 342 (2002) 451-454.
[Non-patent document 4]
Journal of Alloys and Compounds 342 (2002) 473-476.
[0010]
[Patent Document 1]
JP-A-59-189937 [Patent Document 2]
Japanese Patent Application Laid-Open No. 6-312142 [Patent Document 3]
Japanese Patent Publication No. 5-86260 [Patent Document 4]
Japanese Patent Application Laid-Open No. Hei 5-253486 (Patent No. 3273055)
Japanese Patent Application Laid-Open No. Hei 10-235197 (Patent No. 3243504) [Patent Document 6]
JP 2000-135436 A [Patent Document 7]
JP-A-7-265704 [Patent Document 8]
JP-A-7-126702 [Patent Document 9]
JP-A-10-80636 [Patent Document 10]
JP 2001-276625 A [Patent Document 11]
JP-A-2002-95970
[Problems to be solved by the invention]
All of the conventional so-called copper-based catalysts manufactured by the above-described typical methods carry copper fine particles on the surfaces of oxides and metals, and serve as active sites for the catalytic reaction. At a high temperature (300 ° C.), these catalysts are coarsened by sintering of copper fine particles, and the surface area of copper is extremely reduced, so that the activity is reduced.
[0012]
When NaOH is used as the alkaline aqueous solution, the catalyst of the invention described in Patent Document 7 (Japanese Patent Application Laid-Open No. 7-265704) has a NaOH concentration of 20 to 30% by weight, a dipping time of 1 to 30 minutes, and a ribbon shape. The material is decomposed, and the coarsening due to sintering at high temperature is increased by uniformly dispersing ultrafine particles of rare earth elements, transition metals, noble metals, etc., but the increase in activity due to temperature rise is The decrease in activity due to the deterioration of the catalyst is canceled out, and the heat resistance reaches a peak at 300 ° C. in both cases. This is considered to be because the rapidly solidified amorphous alloy (particularly an Al alloy) changes to an equilibrium structure when the temperature rises a little, and crystallizes to lower the stability of the catalyst. Furthermore, the use of the process of rapid solidification increases costs and lowers product yield.
[0013]
The catalyst of the invention described in Patent Document 10 (Japanese Patent Application Laid-Open No. 2001-276625) has high activity, but its activity peaks at 320 ° C. or higher, and the heat resistance is not sufficient.
[0014]
Since many catalytic reactions occur at high temperatures, heat resistance and durability are required. For example, when used as a catalyst for a fuel cell requiring heat resistance, heat resistance and durability are particularly problematic. The components other than the copper-based catalyst are mostly composed of noble metals, and are not practical in terms of cost. An object of the present invention is to provide a copper-based catalyst having high activity and excellent heat resistance and durability, and a method for producing the catalyst at a low cost by a process as simple as possible.
[0015]
[Means for Solving the Problems]
The present inventors have studied a heat-resistant copper-based catalyst having the above-described problems and a method for producing the same.As a result, a quasicrystalline Al alloy ingot composed of aluminum, copper, and cobalt was used as a precursor, and this was pulverized. The catalyst comprising fine particles obtained by leaching the particles obtained has high activity, high heat resistance and durability in the steam reforming reaction of methanol, and the catalyst crushes the quasicrystalline Al alloy ingot, The present inventors have found that the obtained particles can be easily produced by leaching treatment with a weak alkaline solution, and have reached the present invention.
[0016]
That is, the present invention provides (1) a composition represented by the general formula: Al _100-abc Cu _a Co _b (provided that 5 atomic% ≦ a ≦ 30 atomic% and 5 atomic% ≦ b ≦ 25 atomic%) Characterized by being composed of composite particles in which Cu nanoparticles and Co nanoparticles are uniformly dispersed and fixed on the surfaces of quasicrystalline Al alloy particles obtained by grinding and leaching a quasicrystalline Al alloy ingot having Heat-resistant catalyst.
Further, the present invention is (2) the general formula _{Al 100-a-b-c} Cu a Co b Fe c ( where 5 atomic% ≦ a ≦ 30 atomic%, 5 atomic% ≦ b ≦ 25 atomic%, c ≦ (10 atomic%) A composite in which Cu nanoparticles and Co nanoparticles are uniformly dispersed and fixed on the surfaces of quasicrystalline Al alloy particles obtained by pulverizing and leaching an ingot of a quasicrystalline Al alloy having a composition represented by 10 atomic%). A heat-resistant catalyst comprising particles.
[0017]
Further, the present invention provides (3) leaching the composite fine particles obtained by pulverizing an ingot of a quasicrystalline Al alloy having a composition represented by the above general formula (1) or (2) with an aqueous alkali solution. A method for producing a heat-resistant catalyst according to the above (1) or (2), which is characterized in that:
The present invention also provides (4) the method for producing a heat-resistant catalyst according to (3) above, wherein the concentration range of the alkali compound in the aqueous alkali solution is 2 to 8% by weight.
The present invention also provides (5) the method for producing a heat-resistant catalyst according to the above (3) or (4), wherein the aqueous alkali solution is an aqueous sodium carbonate (Na ₂ CO ₃ ) or sodium hydrogen carbonate (NaHCO ₃ ) solution. ,.
Further, the present invention comprises (6) a step of heat-treating the ingot of the quasicrystalline Al alloy in an inert atmosphere to grow a quasicrystalline phase in the alloy, the production of the heat resistant catalyst according to the above (3). The way.
[0018]
Usually, as the temperature increases, the molecules become more active, the activity increases, and the rate of hydrogen generation increases. Such a proportionality is limited only when there is no change in the nature of the catalyst. In general, an increase in activity due to an increase in temperature negates a decrease in activity due to deterioration of the catalyst. However, the catalyst of the present invention has a feature that the catalyst activity is linearly increased even at 400 ° C.
[0019]
BEST MODE FOR CARRYING OUT THE INVENTION
The catalyst of the present invention uses, as a precursor, a quasicrystalline Al alloy composed of aluminum, copper, and cobalt or aluminum, copper, cobalt, and iron. The composition of the quasicrystalline Al alloy is 5% to 30% of copper, 5% to 25% of cobalt, 0% to 10% of iron, and the remaining amount of aluminum in atomic%. The AlCuCo-based alloy has a quasicrystal forming composition range that is considerably wider than that of AlCuFe. In particular, Cu / Co substitution is possible in a wider composition range than Cu / Fe substitution. The formation of the quasicrystal makes it possible to easily obtain fine primary particles having a large surface area due to the fragility of the quasicrystal itself.
[0020]
If the copper content of the quasicrystalline Al alloy is less than 5 atomic%, quasicrystals will not be formed and the Cu particles carrying the catalyst will be small, so high activity cannot be expected. On the other hand, if the content is more than 30 atomic%, a quasicrystal is not formed, and sintering due to Cu is liable to occur. If the cobalt content is less than 5 atomic%, no quasicrystal is formed. On the other hand, if it exceeds 25 atomic%, no quasicrystal is formed. Further, when Fe is added to form a quaternary alloy, quasicrystals are formed in a wider composition range and the catalytic activity can be increased, but when iron exceeds 10 atomic%, formation of quasicrystals becomes difficult. .
[0021]
In the present invention, the quasicrystalline Al alloy used as a raw material for the production of the catalyst has a regular decagonal (two-dimensional) quasicrystal structure that has no periodicity and has a ten-fold symmetry not found in crystals. Since the quasicrystals of these compositions are known as stable phases, the melting point reaches around 1020 ° C. and the quasicrystal structure is maintained up to the melting point. Therefore, if heat treatment is performed at a high temperature of about 800 ° C., a “quasicrystal” composed of three elements having a good single phase can be obtained by the growth of the quasicrystal phase.
[0022]
Since the quasicrystalline phase has no periodicity and no specific slip surface, plastic deformation due to dislocation motion is unlikely to occur and has the property of being brittle. When used as a catalyst, the quasicrystal must have a high surface area in order to obtain sufficient activity, so the quasicrystal must be excellent in pulverizability, easily pulverized to the micron order, and capable of achieving a high surface area. It is. The quasicrystalline Al alloy in the present invention includes not only an alloy composed of a quasicrystalline single phase but also a mixed phase structure containing an approximate crystal and another crystal phase in addition to the quasicrystalline phase.
[0023]
The quasicrystalline Al alloy having a specific composition as a precursor of the heat-resistant copper-based catalyst of the present invention is prepared by melting a pure metal (pure Al, pure Cu, pure Co, pure Fe) having the above composition ratio by a normal melting casting method, for example, arc welding. It is obtained as an ingot by melting and melting and casting. Further, the ingot is subjected to a heat treatment in a temperature range of about 700 to 850 ° C. while preventing oxidation in a vacuum or an inert atmosphere, so that the quasicrystalline phase can be made uniform.
[0024]
In the catalyst production method of the present invention, first, the obtained ingot of the quasicrystalline Al alloy is pulverized in order to increase the surface area as a catalyst. The pulverization is performed, for example, by charging an alloy obtained by crushing an ingot into an agate mortar and using a planetary ball mill. The particle size distribution range of the particles obtained at that time is about 1 μm to 100 μm, preferably 5 μm to 50 μm.
[0025]
The composite fine particle catalyst of the present invention is produced by subjecting the thus obtained particles to a leaching treatment. The treatment solution used for the leaching treatment uses an alkaline aqueous solution that is basic and reacts with aluminum.However, when leaching is performed with a commonly used NaOH aqueous solution, the reach of the NaOH aqueous solution is too strong, and Cu nanoparticles and Co nanoparticles are generated. Since it becomes difficult to form a uniformly dispersed catalyst layer, it is particularly preferable to use an aqueous solution of sodium carbonate (Na ₂ CO ₃ ) or sodium hydrogen carbonate (NaHCO ₃ ) having a medium or weak basicity. The concentration range of the alkali compound in the aqueous alkali solution is preferably about 2 to 8% by weight. If the amount is less than 2% by weight, the reach does not proceed sufficiently, and if the amount exceeds 8% by weight, the reaction is accelerated and it is difficult to control the reach, which is not preferable.
[0026]
By leaching using these low-concentration aqueous alkali solutions, the thin film of alumina formed on the surface of the quasicrystalline alloy particles is removed, and aluminum is eluted from a considerably thin layer on the surface of the quasicrystalline alloy particles. The leaching temperature may be in the range of 0 to 90 ° C., and the elution rate increases as the temperature increases, but it is preferable to perform the heating at around room temperature without heating. The elution amount by leaching with a low-concentration aqueous alkali solution is preferably about 0.5 to 40% by weight. If it is less than 0.5% by weight, the elution of Al is insufficient and the surface area becomes small, and if it exceeds 40% by weight, the quasi-crystal structure is broken and the stability of the catalyst is lowered, which is not preferable. More preferably, it is about 5 to 20% by weight. When the concentration of the aqueous alkali solution is high, a considerable amount of Al is eluted from the alloy particles, and the proportion of the fine particles fixed on the particle surface is overwhelmingly large, which is not preferable.
[0027]
By this leaching, fine copper particles (Cu nanoparticles) can be precipitated on the particle surface. By performing the leaching treatment on the AlCuCo quasicrystal, composite particles in which Cu nanoparticles and Co nanoparticles are uniformly dispersed and fixed on the surfaces of the quasicrystal Al alloy particles are obtained. The powder of the obtained composite fine particles is filtered, washed well, and then dried. The specific surface area of the obtained composite fine particles is about 5 to 40 m ² / g. Basically, there is almost no change in the size of the primary particles due to leaching, so the increase in surface area comes from the network-like microstructure generated on the surface of the quasicrystal. As described above, according to leaching with a low-concentration aqueous alkali solution, only a region of about 200 nm is eluted from the surface of the quasicrystal, and the presence of the central quasicrystal plays an important role in the stability of the catalyst. Therefore, despite this surface area, high catalytic activity is exhibited.
[0028]
With the composite fine particles having such a structure, other catalytic reactions by Co particles are expected in addition to the catalytic function of Cu nanoparticles. This point is different from the function of Fe in the AlCuFe quasicrystal. In fact, it is the nanometal particles deposited on the surface of the quasicrystal that are responsible for the catalytic activity, and the quasicrystal functions as a “support”. In the AlCuCoFe quasicrystal, Fe exists as nanoparticles of Fe or Fe oxide. Since Fe or its oxide also has the property of not dissolving as a solid in Cu, it has an effect of preventing sitering due to diffusion of Cu atoms.
[0029]
The composite fine particles of the present invention are formed as necessary and used as a catalyst. The composite fine particles can be used by being supported on a carrier. The type of the reactor using the catalyst of the present invention is not particularly limited, and it is used for a fixed bed flow type reactor or a fluidized bed reactor, and can be used not only for a gas phase reaction but also for a liquid phase reaction.
[0030]
【Example】
Next, the present invention will be described more specifically with reference to examples.
Example 1
Al-Cu-Co quasicrystal / Na ₂ CO ₃ leaching 4.514 g of Al, 2.453 g of Cu, 3.033 g of Co were weighed, placed in a water-cooled copper hearth, and arc-melted under an argon atmosphere. It was cooled in a copper hearth as it was to obtain 10 g of an ingot of Al ₆₅ Co ₂₀ Cu ₁₅ . This was ground into a powder of 1 mm or less in an alumina pot, vacuum-sealed in a quartz tube, and heat-treated at 800 ° C. for 24 hours. After the heat treatment, it was taken out of the quartz tube and further ground with a planetary ball mill. The particle size distribution range of the obtained particles was 1 μm to 100 μm. The resulting Al-Cu-Co quasicrystalline alloy particles was 4 hours leaching treated with 5 wt% of _Na 2 CO ₃ (sodium carbonate) solution. This was filtered, washed well with water, and dried. The elution amount was 3.6% by weight. As a result, composite particles in which Cu nanoparticles and Co nanoparticles were uniformly dispersed and fixed on the surfaces of the quasicrystalline Al alloy particles were obtained. The specific surface area was about 30 m ² / g.
[0031]
Example 2
Al-Cu-Co quasicrystal / NaHCO ₃ leaching The same conditions as in Example 1 were used except that 5 wt% of sodium hydrogen carbonate (NaHCO ₃ ) was used instead of Na ₂ CO ₃ in Example 1. The elution amount was 0.9% by weight. As a result, composite particles in which Cu nanoparticles and Co nanoparticles were uniformly dispersed and fixed on the surfaces of the quasicrystalline Al alloy particles were obtained. The specific surface area was about 5 m ² / g.
[0032]
Example 3
Al-Cu-Co-Fe quasicrystal / Na ₂ CO ₃ leaching Al: 4.492 g, Cu: 3.7443 g, Co: 0.906 g, Fe: 0.858 g were weighed and placed in a water-cooled copper hearth. Arc melting was performed in an argon atmosphere to obtain 10 g of an ingot of Al ₆₃ Cu ₂₃ Co ₆ Fe ₆ . This was ground into a powder of 1 mm or less in an alumina pot, vacuum-sealed in a quartz tube, and heat-treated at 800 ° C. for 24 hours. After the heat treatment, it was taken out of the quartz tube and further ground with a planetary ball mill. The particle size distribution range of the obtained particles was 1 μm to 100 μm. The obtained particles were subjected to a leaching treatment with 5 wt% of Na ₂ CO ₃ (sodium carbonate) for 4 hours. This was filtered, washed well with water, and dried. The elution amount was 3.0% by weight. As a result, composite particles in which Cu nanoparticles and Co nanoparticles were uniformly dispersed and fixed on the surfaces of the quasicrystalline Al alloy particles were obtained. The specific surface area was about 25 m ² / g.
[0033]
Example 4
Al-Cu-Co quasicrystal / NaOH leaching The same conditions as in Example 1 were used except that 5 wt% sodium hydroxide (NaOH) was used instead of Na ₂ CO ₃ in Example 1. The elution amount was 37.8% by weight. As a result, composite particles in which Cu nanoparticles and Co nanoparticles were uniformly dispersed and fixed on the surfaces of the quasicrystalline Al alloy particles were obtained. The specific surface area was about 17 m ² / g.
[0034]
Comparative Example 1
Al-Cu-Fe quasicrystal / 5 wt% NaOH leaching 4.29 g of Al, 4.01 g of Cu, and 1.69 g of Fe were weighed, placed in a water-cooled copper hearth, and arc-melted under an argon atmosphere. 10 g of ₆₅ Co ₂₀ Cu ₁₅ ingot was obtained. This was ground into a powder of 1 mm or less in an alumina pot, vacuum-sealed in a quartz tube, and heat-treated at 800 ° C. for 24 hours. After the heat treatment, it was taken out of the quartz tube and further ground with a planetary ball mill. The particle size distribution range of the obtained particles was 0.1 μm to 100 μm. The obtained particles were subjected to a leaching treatment with 5 wt% of NaOH (sodium hydroxide) for 4 hours. This was filtered, washed well with water, and dried. The elution amount was 22.6% by weight. As a result, composite particles in which Cu nanoparticles were uniformly dispersed and fixed on the surfaces of the quasicrystalline Al alloy particles were obtained. The specific surface area was about 25 m ² / g.
[0035]
Comparative Example 2
Al-Cu-Fe quasicrystal / 20 wt% NaOH leaching The same conditions as in Comparative Example 1 were used except that 20 wt% sodium hydroxide (NaOH) was used instead of 5 wt% NaOH in Comparative Example 1. The elution amount was 27.7% by weight. The specific surface area was about 23 m ² / g.
[0036]
Comparative Example 3
Raney Cu / NaOH development In the same manner as in Example 1, using 2.980 g of Al and 7.020 g of Cu, 10 g of an alloy ingot of Al ₅₀ Cu ₅₀ was prepared, and the alloy was mixed with a 40-fold amount of a 20% aqueous NaOH solution. The powder was charged little by little over 30 minutes, leached and washed with water. The elution amount was 29.8% by weight. This produced a Raney Cu catalyst. The specific surface area was about 32 m ² / g.
[0037]
Comparative Example 4
The leaching was not performed on the Al-Cu-Co quasicrystal alloy particles produced in Example 1. The specific surface area was about 1 m ² / g.
[0038]
Catalyst activity test 0.6 g of the catalyst was weighed, and a fixed-bed flow reactor was set at normal pressure and a reaction temperature of 240 to 400 ° C., and a mixed solution having a water / methanol molar ratio of 1.5 was passed. The generated gas was analyzed by gas chromatography, and the activities of the catalysts of Examples 1 to 4 and Comparative Examples 1 to 4 were evaluated based on the hydrogen generation rate. The results are shown in FIG.
[0039]
From the above test, the catalyst activity of the conventional Raney Cu catalyst decreases when the temperature exceeds 300 ° C., whereas the catalyst activity of the catalysts of Examples 1 to 4 increases even when the temperature exceeds 300 ° C. In the case of leaching (Example 4), high activity, good heat resistance and durability exhibiting the same tendency as in the case of the Al-Cu-Fe quasicrystal are exhibited. In particular, when leaching is performed with sodium carbonate or sodium hydrogen carbonate. (Examples 1 to 3) have a feature that the catalytic activity increases in proportion to the temperature rise even when the temperature exceeds 360 ° C., and the catalyst of the present invention shows a higher activity and a better It is clear that it has heat resistance and durability.
[0040]
【The invention's effect】
As is clear from the above description, a composite in which Cu nanoparticles and Co nanoparticles are uniformly dispersed and fixed on the surface of quasicrystalline Al alloy particles as a precursor using the quasicrystalline Al alloy produced by the method of the present invention. The Cu-based catalyst composed of particles has high activity, is excellent in heat resistance, has additional catalytic activity due to containing Co or Co and Fe, and has excellent heat resistance and durability. Further, since the catalyst of the present invention is easily produced by pulverizing and leaching an ingot produced by a usual melting casting method, it can be produced by a simple process at low cost.
[Brief description of the drawings]
FIG. 1 is a graph showing the results of evaluating the activities of catalysts of Examples 1 to 4 and Comparative Examples 1 to 4.

Claims (6)

A quasicrystalline Al alloy ingot having a composition represented by the general formula Al _100-abc Cu _a Co _b (5 at% ≦ a ≦ 30 at%, 5 at% ≦ b ≦ 25 at%) A heat-resistant catalyst comprising composite particles in which Cu nanoparticles and Co nanoparticles are uniformly dispersed and fixed on the surfaces of quasicrystalline Al alloy particles obtained by pulverization and leaching. Formula _{Al 100-a-b-c} Cu a Co b Fe c ( where 5 atomic% ≦ a ≦ 30 atomic%, 5 atomic% ≦ b ≦ 25 atomic%, c ≦ 10 atomic%) a composition represented by Characterized in that it is composed of composite particles in which Cu nanoparticles and Co nanoparticles are uniformly dispersed and fixed on the surfaces of quasicrystalline Al alloy particles obtained by grinding and leaching a quasicrystalline Al alloy ingot. catalyst. 3. The heat-resistant catalyst according to claim 1, wherein the composite fine particles obtained by pulverizing an ingot of a quasicrystalline Al alloy having a composition represented by the general formula according to claim 1 or 2 are leached with an aqueous alkali solution. Manufacturing method. The method for producing a heat-resistant catalyst according to claim 3, wherein the concentration range of the alkali compound in the aqueous alkali solution is 2 to 8% by weight. The method for producing a heat-resistant catalyst according to claim 3 or 4, wherein the alkaline aqueous solution is a sodium carbonate (Na ₂ CO ₃ ) or sodium hydrogen carbonate (NaHCO ₃ ) aqueous solution. The method for producing a heat-resistant catalyst according to claim 3, further comprising a step of heat-treating the ingot of the quasicrystalline Al alloy in an inert atmosphere to grow a quasicrystalline phase in the alloy.

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