Pt-cuga o2 / c composite catalyst for direct methanol fuel cell anode and preparation method thereof

Abstract

The application discloses a Pt-CuGaO2 / C composite catalyst for an anode of a direct methanol fuel cell and a preparation method thereof; the catalyst takes a copper gallium oxide with a structure of ABO2 as a carrier of nano platinum, and the loading of the nano platinum is 5-15 wt.%; during the preparation, the copper gallium oxide carrier is synthesized by a hydrothermal method, the nano platinum is reduced by a polyol heating method, and the carbon powder is loaded by a microwave intermittent reaction method, so that the Pt-CuGaO2 / C composite direct methanol fuel cell anode catalyst with high efficiency and stability is obtained; the 5 wt.% catalyst obtains a 653.4 mA / mg Pt ‑1 mass activity, 2.53 mA / cm 2 specific activity of 25.83 m 2 A / g of electrochemical active area, and a ratio (I f / I b ) of a forward peak current density to a reverse peak current density of an index of carbon monoxide poisoning resistance is 1.50; all the catalytic activity indexes are better than those of a commercial Pt / C catalyst, and the Pt-CuGaO2 / C composite direct methanol fuel cell anode catalyst has a potential application prospect.

Description

Technical Field

[0001] This invention belongs to the field of fuel cell technology and relates to a Pt-CuGaO2 / C composite catalyst for the anode of a direct methanol fuel cell and its preparation method. Specifically, it relates to a Pt-CuGaO2 / C composite catalyst for the anode of a direct methanol fuel cell based on a copper gallium oxide support and its preparation method. Background Technology

[0002] Methanol, as a carrier of carbon and hydrogen energy, possesses the fundamental physical property of being liquid at room temperature and pressure, making its production, storage, transportation, and energy conversion safer and more convenient, thus attracting widespread attention. The electrochemical methanol oxidation reaction, as the anode reaction in direct methanol fuel cells, is a key route for renewable energy technology. However, significant challenges remain in preparing low-cost, carbon monoxide-resistant, and stable electrocatalysts for direct methanol fuel cell anodes, which is also a major issue limiting the commercialization of direct methanol fuel cells. Current anode catalysts suffer from problems such as susceptibility to CO poisoning, high overpotential, poor reaction kinetics, and high precious metal content, all of which limit the application of direct methanol fuel cells. Therefore, developing novel anode catalyst supports for direct methanol fuel cells is beneficial for reducing precious metal content, improving stability, and lowering costs. Thus, preparing a non-precious metal system with good stability that facilitates the uniform dispersion of precious metals on its surface is of great significance for developing efficient and reliable direct methanol fuel cells.

[0003] Copper and gallium are more widely distributed and cheaper than precious metals. However, research on copper-gallium oxide as an anode catalyst support for direct methanol fuel cells is limited, especially as a support for platinum-based catalysts. By adjusting the amount of mineralizer KOH added in the precursor and the ratio of copper and gallium salts, and by optimizing the hydrothermal method to add a certain amount of surfactant, hexagonal plate-like copper-iron ore copper-gallium oxide was obtained as an anode catalyst support. This significantly improved the catalyst's resistance to poisoning, the dispersibility of precious metal nanoparticles, and its cycle stability. Furthermore, due to gallium's strong affinity for oxygen, the copper-iron ore copper-gallium oxide support can also provide a large number of oxygen adsorbate species during the catalytic oxidation of methanol, promoting the complete oxidation of methanol and thus improving the catalyst's catalytic kinetics.

[0004] Based on existing technologies, this invention proposes for the first time a novel copper-iron ore-structured copper-gallium oxide as an anode catalyst support for direct methanol fuel cells. It can achieve extremely low precious metal usage, good stability under acidic conditions, and strong resistance to carbon monoxide poisoning. Its performance is superior to current commercial Pt / C catalysts, and it has good application prospects. Summary of the Invention

[0005] The purpose of this invention is to provide a Pt-CuGaO2 / C composite catalyst for the anode of a direct methanol fuel cell and its preparation method; this catalyst is used to reduce the cost of the catalyst and improve its stability, activity and carbon monoxide poisoning resistance.

[0006] The objective of this invention is achieved through the following technical solution:

[0007] This invention relates to a Pt-CuGaO2 / C composite catalyst based on a copper gallium oxide support, characterized in that the catalyst has platinum nanoparticles loaded on the surface of a copper-iron oxide-structured CuGaO2 oxide support, wherein the mass of the platinum nanoparticles accounts for 5-15 wt.% of the total mass of the composite catalyst, and the mass of C accounts for 30-50 wt.% of the total mass of the composite catalyst. C is also loaded on the surface of the Pt-CuGaO2 oxide support.

[0008] As one embodiment, the platinum nanoparticles have a particle size of 5-10 nm; the CuGaO2 oxide support has a hexagonal sheet structure with a particle size between 5-8 μm, and the platinum nanoparticles are uniformly dispersed on the surface of the CuGaO2 oxide.

[0009] This invention also relates to a hydrothermal preparation method of a Pt-CuGaO2 / C composite catalyst, the method comprising the following steps:

[0010] S1. Using water and ethylene glycol as solvents, dissolve copper nitrate and gallium nitrate, add potassium hydroxide as a mineralizing agent, and hexadecyltrimethylammonium bromide (CTAB) as a morphology improver and surfactant. Stir in a water bath for 0.5-2 h (stir at 0-4℃ for 0.5-2 h to obtain a blue suspension), transfer it to a hydrothermal reactor (with a tetrafluoroethylene hydrothermal reactor liner), and react at 160℃-200℃ for 12-24 h to obtain a yellowish-brown suspension precursor;

[0011] S2. The yellowish-brown suspension precursor (centrifuged at 6000-10000 rpm at room temperature) was separated to remove the supernatant, and a yellow solid was obtained. The obtained solid was washed (washed 1-3 times with dilute hydrochloric acid, dilute ammonia, deionized water, and anhydrous ethanol, respectively) to remove impurities and then vacuum dried (dried in a vacuum drying oven at 65-80℃ for 12-24 h). Water and ethylene glycol were added as a mixed solvent, and chloroplatinic acid was reduced by polyol thermal method to obtain copper gallium oxide Pt-CuGaO2 loaded with platinum nanoparticles.

[0012] S3. Pt-CuGaO2 and carbon powder are loaded at a mass ratio of 1:1 to 3:1 by microwave intermittent reaction method to obtain Pt-CuGaO2 / C composite catalyst.

[0013] The optimized hydrothermal method employed in this invention yields a purer crystal phase compared to traditional impregnation and co-precipitation methods. The reaction process is also more environmentally friendly, resulting in a uniformly distributed hexagonal lamellar structure that increases specific surface area and stability. The prepared copper-gallium oxide (Pt-CuGaO2) exhibits a copper-iron ore structure, which demonstrates superior stability and activity compared to other structures such as brucite and spinel. Furthermore, the unique layered structure of the copper-iron ore oxide exposes more gallium atoms, providing more methanol adsorption sites and active hydroxide intermediates, thus promoting the anodic catalytic process.

[0014] As one implementation scheme, in step S1, potassium hydroxide is prepared into a 2M solution and added dropwise to the solution of copper nitrate and gallium nitrate while stirring to ensure the stability of the suspension.

[0015] As one implementation scheme, in step S2, NaOH is also added as a mineralizing agent to the polyol thermal reduction of chloroplatinic acid system. Each 100 mg of copper-iron ore CuGaO2 oxide support corresponds to 26.67-40 mg of H2PtCl6·6H2O and 160 mg of NaOH.

[0016] As one implementation scheme, in step S3, Pt-CuGaO2 and carbon powder are ultrasonically dispersed in isopropanol at a mass ratio of 1:1-3:1, dried at 60-80℃ for 10-14 hours, and then subjected to microwave intermittent reaction.

[0017] In one implementation scheme, in step S1, the molar ratio of potassium hydroxide to copper nitrate and gallium nitrate is 4:1:1 to 8:1:1.

[0018] As one implementation, in step S1, the concentration of CTAB in the mixture is 0.01-0.1 mol / L.

[0019] As one implementation scheme, in step S1, the water bath temperature is 0-4℃.

[0020] As one implementation scheme, in step S2, the reaction temperature corresponding to the thermal reduction of the polyol is 120-160℃, and the reaction time is 8-12h.

[0021] As one implementation scheme, in step S3, the microwave intermittent reaction method involves heating at 2000–3000 MHz and 500–1000 W for 10–20 seconds with an interval of 60–120 seconds, for six cycles. Preferably, the method involves heating at 2000 MHz and 500–700 W for 10–20 seconds with an interval of 60–120 seconds, for six cycles.

[0022] In some embodiments, the preparation steps are as follows:

[0023] 1) Dissolve copper nitrate, gallium nitrate and 0.015 mol / L CATB in a molar ratio of 1:1 in 70 mL of a 1:1 (volume ratio) mixture of deionized water and ethylene glycol, and stir in a water bath at 4 °C until dissolved;

[0024] 2) Add a certain amount of potassium hydroxide to the solution in 1) above and stir until a light blue turbid liquid appears;

[0025] 3) Transfer the solution from step 2) above to a hydrothermal reactor and heat and stir at 160-200℃ for 12-24 hours;

[0026] 4) Pour the yellowish-brown suspension obtained in 3) above into a 50mL round-bottom centrifuge tube, centrifuge at 6000-10000rpm at room temperature to remove the supernatant and obtain a yellow solid. Wash the obtained solid 1-3 times with dilute hydrochloric acid, dilute ammonia, deionized water and anhydrous ethanol respectively to remove impurities. Dry the washed material in a vacuum drying oven at 65-80℃ for 12-24h to obtain a yellow solid copper gallium oxide.

[0027] 5) Weigh 100 mg of the above copper-iron oxide and ultrasonically disperse it in a 1:1 (volume ratio) mixture of deionized water and ethylene glycol in 60 mL. Add 26.67 mg of H2PtCl6·6H2O and 160 mg of mineralizing agent NaOH and mix well. Then transfer the mixture to a 100 mL hydrothermal reactor and react at 120 °C for 10 hours. After the product is cooled to room temperature, centrifuge at 6000 rpm and wash twice each with dilute hydrochloric acid, deionized water and anhydrous ethanol. Dry the product in a vacuum drying oven at 70 °C to obtain 81 mg of platinum-loaded copper gallium oxide Pt-CuGaO2.

[0028] 6) The Pt-CuGaO2 obtained in 5) and an equal mass of purchased Cabot Vulcan XC-72 carbon powder were ultrasonically dispersed in 20 mL of isopropanol for 1 hour. The mixture was dried in a vacuum drying oven at 70 °C for 12 h. The mixed powder was placed in a microwave oven and heated intermittently for six cycles at 2000–3000 MHz and 500–1000 W. After cooling, the copper gallium oxide-supported direct methanol fuel cell composite anode electrocatalyst Pt-CuGaO2 / C was obtained.

[0029] This invention also relates to the application of Pt-CuGaO2 / C composite catalysts as anode catalysts in direct methanol fuel cells.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] 1) The Pt-CuGaO2 / C composite electrocatalyst based on a copper gallium oxide support prepared in this invention is used for anode catalysis in direct methanol fuel cells. There is a strong metal-support interaction between Pt and CuGaO2, and the oxophilic gallium support provides abundant hydroxide species and active sites on the catalyst surface; the resulting composite catalyst system achieved an efficiency of 653.4 mA / mg. Pt -1 Mass activity, 2.53 mA / cm 2 Specific activity and 25.83m 2 The ratio of the forward peak current density to the reverse peak current density (Ig) is an indicator of the resistance to carbon monoxide poisoning. f / I b The coefficient of performance was 1.50, and all catalytic activity indicators were better than those of commercial Pt / C catalysts.

[0032] 2) The synthesis method used in this invention is a hydrothermal method, which does not produce toxic waste. Compared with the sol-gel method, ion exchange method, and solid-phase reaction method, the synthesis process does not produce toxic and harmful substances, which meets the requirements of green chemistry. The obtained product has a uniform particle size distribution, which improves the stability of platinum nanoparticle loading. At the same time, the uniform morphology and gallium have stronger hydrophilicity, and have higher catalytic activity and anti-poisoning performance compared with copper aluminum oxide and other systems. Attached Figure Description

[0033] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0034] Figure 1 This is a TEM image of the Pt-CuGaO2 / C composite electrocatalyst in Example 1;

[0035] Figure 2 The XRD pattern of CuGaO2 used in Example 1;

[0036] Figure 3 The CV curve of the Pt-CuGaO2 / C composite electrocatalyst in Example 1 is shown in 0.5M H2SO4 + 1M CH3OH. Detailed Implementation

[0037] The present invention will be described in detail below with reference to embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way. It should be noted that those skilled in the art can make several adjustments and improvements without departing from the concept of the present invention. These all fall within the protection scope of the present invention.

[0038] Example 1

[0039] 1) Weigh 12 mmol of Cu(NO3)2·3H2O (2.89 g) and 12 mmol of Ga(NO3)3·xH2O (1.85 g) and dissolve them in 70 mL of a 1:1 (volume ratio) mixture of deionized water and ethylene glycol. Stir at 4 °C until dissolved.

[0040] 2) Add 0.1 mmol (38 mg) of CTAB to the solution in 1) above and stir for 10 minutes;

[0041] 3) Add 2M KOH solution to the solution in 2) above until the pH reaches 13, stir for 45 minutes to obtain a uniform blue suspension;

[0042] 4) Transfer the suspension from 3) above to the PTFE liner of a 100mL hydrothermal autoclave, place the autoclave in a forced-air drying oven and heat to 200℃, and leave for 24 hours;

[0043] 5) After the reaction is complete, slowly cool it to room temperature, centrifuge at 8000 rpm to remove the supernatant, and obtain a yellowish-brown solid;

[0044] 6) The yellowish-brown solid obtained in step 5) above was washed twice with 1M dilute hydrochloric acid, 1M dilute ammonia, deionized water and anhydrous ethanol respectively, and dried in a vacuum drying oven at 70°C for 18 hours to obtain 1.28g of pale yellow solid CuGaO2.

[0045] 8) Weigh 100 mg of the above copper gallium copper iron oxide, ultrasonically disperse it in a 60 mL mixture of deionized water and ethylene glycol in a 1:1 (volume ratio), add 26.67 mg of H2PtCl6·6H2O and 160 mg of NaOH, mix well, transfer to a 100 mL hydrothermal reactor, react at 120 °C for 10 hours, cool the product to room temperature, centrifuge at 6000 rpm, wash twice each with dilute hydrochloric acid, deionized water and anhydrous ethanol, and dry in a vacuum drying oven at 70 °C to obtain 81 mg of platinum-loaded copper gallium oxide Pt-CuGaO2;

[0046] 9) The Pt-CuGaO2 obtained in 8) and an equal mass of purchased Cabot Vulcan XC-72 carbon powder were ultrasonically dispersed in 20 mL of isopropanol for 1 hour and dried in a vacuum drying oven at 70 °C. The mixed powder was placed in a microwave oven and heated for 20 s at 2000 MHz and 700 W for 60 s intervals for six cycles. After cooling, the copper gallium oxide-supported direct methanol fuel cell composite anode electrocatalyst Pt-CuGaO2 / C was obtained.

[0047] The morphology of the Pt-CuGaO2 / C obtained in Example 1 was analyzed using transmission electron microscopy (TEM), and the test results are as follows: Figure 1 As shown, by Figure 1It can be seen that the oxide support has a uniform hexagonal sheet structure.

[0048] The morphology of CuGaO2 obtained in Example 1 was analyzed using X-ray diffraction (XRD), and the test results are as follows: Figure 2 As shown, by Figure 2 It can be seen that it is the pure phase of CuGaO2.

[0049] Electrochemical cyclic voltammetry was used to measure the methanol catalytic activity of the prepared anodic oxidant. The test was conducted on an electrochemical workstation (CHI 760E, Shanghai Chenhua) using a traditional three-electrode system, with a graphite sheet as the counter electrode, a standard calomel electrode (SCE) as the reference electrode, and a glassy carbon electrode (3 mm in diameter) coated with catalyst as the working electrode.

[0050] The catalyst slurry was prepared by dispersing 10 mg Pt-CuGaO2 / C in 2 mL of water containing 40 μL of 0.5 wt% Nafion and sonicating for 30 min to form a homogeneous suspension. 10 μL of catalyst ink was dropped onto a polished glassy carbon electrode and dried to serve as the working electrode.

[0051] In cyclic voltammetry, cyclic voltammetry was performed in a 1.0 mol / L CH3OH / 0.5 mol / L H2SO4 aqueous solution under an argon atmosphere at a scan rate of 50 mV / s. The test results are as follows: Figure 3 As shown, by Figure 3 It can be seen that the mass activity density is much higher than that of commercial Pt / C catalysts.

[0052] Comparative Example 1

[0053] 1) Weigh 12 mmol of Cu(NO3)2·3H2O (2.89 g) and 12 mmol of Ga(NO3)3·xH2O (1.85 g) and dissolve them in 70 mL of a 1:1 (volume ratio) mixture of deionized water and ethylene glycol. Stir at 4 °C until dissolved.

[0054] 2) Add 0.1 mmol (38 mg) of CTAB to the solution in 1) above and stir for 10 minutes;

[0055] 3) Add 2M KOH solution to the solution in 2) above until the pH reaches 13, stir for 45 minutes to obtain a uniform blue suspension;

[0056] 4) Transfer the suspension from 3) above to the PTFE liner of a 100mL hydrothermal autoclave, place the autoclave in a forced-air drying oven and heat to 200℃, and leave for 24 hours;

[0057] 5) After the reaction is complete, slowly cool it to room temperature, centrifuge at 8000 rpm to remove the supernatant, and obtain a yellowish-brown solid;

[0058] 6) The yellowish-brown solid obtained in step 5) above was washed twice with 1M dilute hydrochloric acid, 1M dilute ammonia, deionized water and anhydrous ethanol respectively, and dried in a vacuum drying oven at 70°C for 18 hours to obtain 1.28g of pale yellow solid CuGaO2.

[0059] 7) Weigh 100 mg of the above copper gallium copper iron oxide and ultrasonically disperse it in a 1:1 (volume ratio) mixture of deionized water and ethylene glycol in 60 mL. Add 26.67 mg of H2PtCl6·6H2O and 160 mg of NaOH and mix well. Transfer the mixture to a 100 mL hydrothermal reactor and react at 120 °C for 10 hours. After the product is cooled to room temperature, centrifuge at 6000 rpm and wash twice each with dilute hydrochloric acid, deionized water, and anhydrous ethanol. Dry the product in a vacuum drying oven at 70 °C to obtain 87 mg of platinum-loaded copper gallium oxide Pt-CuGaO2.

[0060] Electrochemical tests were performed on the obtained catalyst, but no methanol oxidation current was obtained due to the high basic resistance.

[0061] Comparative Example 2

[0062] 1) Weigh 12 mmol of Cu(NO3)2·3H2O (2.89 g) and 12 mmol of Ga(NO3)3·xH2O (1.85 g) and dissolve them in 70 mL of a 1:1 (volume ratio) mixture of deionized water and ethylene glycol. Stir at 4 °C until dissolved.

[0063] 2) Add 0.1 mmol (38 mg) of CTAB to the solution in 1) above and stir for 10 minutes;

[0064] 3) Add 2M KOH solution to the solution in 2) above until the pH reaches 13, stir for 45 minutes to obtain a uniform blue suspension;

[0065] 4) Transfer the suspension from 3) above to the PTFE liner of a 100mL hydrothermal autoclave, place the autoclave in a forced-air drying oven and heat to 200℃, and leave for 24 hours;

[0066] 5) After the reaction is complete, slowly cool it to room temperature, centrifuge at 8000 rpm to remove the supernatant, and obtain a yellowish-brown solid;

[0067] 6) The yellowish-brown solid obtained in step 5) above was washed twice with 1M dilute hydrochloric acid, 1M dilute ammonia, deionized water and anhydrous ethanol respectively, and dried in a vacuum drying oven at 70°C for 18 hours to obtain 1.28g of pale yellow solid CuGaO2.

[0068] 8) Weigh 100 mg of the above copper gallium copper iron oxide and 100 mg of XC-72 carbon powder, and ultrasonically disperse them in a 60 mL mixture of deionized water and ethylene glycol in a 1:1 (volume ratio). Add 26.67 mg of H2PtCl6·6H2O and 160 mg of NaOH, mix well, and then transfer to a 100 mL hydrothermal reactor. React at 120 °C for 10 hours. After the product is cooled to room temperature, centrifuge at 6000 rpm, wash twice each with dilute hydrochloric acid, deionized water, and anhydrous ethanol, and dry in a vacuum drying oven at 70 °C to obtain 177 mg of platinum and carbon-loaded copper gallium oxide Pt / C-CuGaO2.

[0069] The obtained catalyst was tested. Due to the one-pot method, a large amount of platinum nanoparticles were directly loaded onto the carbon powder, which did not give full play to the advantages of copper gallium copper iron oxide support. Its methanol oxidation quality activity and anti-poisoning performance were weaker than Pt-CuGaO2 / C, but higher than commercial Pt / C.

[0070] The above description fully demonstrates that the Pt-CuGaO2 / C composite direct methanol fuel cell anode electrocatalyst involved in this invention uses copper gallium oxide with an ABO2 structure as a support for platinum nanoparticles, with a platinum nanoparticle loading of 5 wt%. During preparation, the copper gallium oxide support is synthesized via a hydrothermal method, the platinum nanoparticles are reduced via a polyol thermal method, and carbon powder is loaded via a microwave intermittent reaction method, resulting in a highly efficient and stable Pt-CuGaO2 / C composite direct methanol fuel cell anode catalyst. The 5 wt.% catalyst achieved an A / mg A / V of 653.4 mA. Pt -1 Mass activity, 2.53 mA / cm 2 Specific activity and 25.83m 2 The ratio of the forward peak current density to the reverse peak current density (Ig) is an indicator of the resistance to carbon monoxide poisoning. f / I b The coefficient of performance (COP) is 1.50, and all catalytic activity indicators are better than those of commercial Pt / C catalysts, indicating potential application prospects.

[0071] The specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various modifications or variations within the scope of the claims, which do not affect the essence of the present invention.

Claims

1. A Pt-CuGaO2 / C composite catalyst for the anode of a direct methanol fuel cell based on a copper gallium oxide support, characterized in that, The catalyst is supported on a CuGaO2 oxide support with a copper-iron ore structure and loaded with platinum nanoparticles. The mass of the platinum nanoparticles accounts for 5-15 wt.% of the total mass of the composite catalyst, and the mass of carbon accounts for 30-50% of the total mass of the composite catalyst. The platinum nanoparticles have a particle size of 5-10 nm; the CuGaO2 oxide support has a hexagonal sheet structure with a particle size of 5-8 μm, and the platinum nanoparticles are uniformly dispersed on the surface of the CuGaO2 oxide. The catalyst is prepared by a method comprising the following steps: S1. Using water and ethylene glycol as solvents, dissolve copper nitrate and gallium nitrate. Add potassium hydroxide as a mineralizing agent and hexadecyltrimethylammonium bromide as a surfactant and morphology modifier. Stir in a water bath for 0.5-2 h, then transfer to a hydrothermal reactor at 160°C. o C-200 o After reacting at C for 12-24 h, a yellowish-brown suspension precursor was obtained. S2. The yellowish-brown suspension precursor was centrifuged to remove the supernatant, and a yellow solid was obtained. The obtained solid was washed, impurities were removed, and then vacuum dried to obtain a yellow solid copper gallium oxide. Water and ethylene glycol were added as a mixed solvent, and chloroplatinic acid was reduced by polyol thermal method to obtain copper gallium oxide Pt-CuGaO2 loaded with platinum nanoparticles. S3. Pt-CuGaO2 and carbon powder are loaded at a mass ratio of 1:1 to 3:1 by microwave intermittent reaction method to obtain Pt-CuGaO2 / C composite catalyst.

2. A method for preparing the Pt-CuGaO2 / C composite catalyst according to claim 1, characterized in that, The method includes the following steps: S1. Using water and ethylene glycol as solvents, dissolve copper nitrate and gallium nitrate. Add potassium hydroxide as a mineralizing agent and hexadecyltrimethylammonium bromide as a surfactant and morphology modifier. Stir in a water bath for 0.5-2 h, then transfer to a hydrothermal reactor at 160°C. o C-200 o After reacting at C for 12-24 h, a yellowish-brown suspension precursor was obtained. S2. The yellowish-brown suspension precursor was centrifuged to remove the supernatant, and a yellow solid was obtained. The obtained solid was washed, impurities were removed, and then vacuum dried to obtain a yellow solid copper gallium oxide. Water and ethylene glycol were added as a mixed solvent, and chloroplatinic acid was reduced by polyol thermal method to obtain copper gallium oxide Pt-CuGaO2 loaded with platinum nanoparticles. S3. Pt-CuGaO2 and carbon powder are loaded at a mass ratio of 1:1 to 3:1 by microwave intermittent reaction method to obtain Pt-CuGaO2 / C composite catalyst.

3. The preparation method according to claim 2, characterized in that, In step S1, the molar ratio of gallium nitrate to copper nitrate is 1:

1.

4. The preparation method according to claim 2, characterized in that, In step S1, the concentration of hexadecyltrimethylammonium bromide in the mixture is 0.01-0.1 mol / L.

5. The preparation method according to claim 2, characterized in that, In step S1, the water bath temperature is 0-4°C. o C.

6. The preparation method according to claim 2, characterized in that, In step S2, the centrifugation is performed at 6000-10000 rpm at room temperature, and the vacuum drying is performed at 65-80°C. o Vacuum drying at C for 12-24 h.

7. The preparation method according to claim 2, characterized in that, In step S2, the reaction temperature corresponding to the thermal reduction of the polyol is 120-160°C. o C, the reaction time is 8-12 hours.

8. The preparation method according to claim 2, characterized in that, In step S3, the microwave intermittent reaction method involves heating at 2000 MHz and 500-700 W for 10-20 seconds with an interval of 60-120 seconds, for six cycles.

9. The use of a Pt-CuGaO2 / C composite catalyst according to claim 1, or a Pt-CuGaO2 / C composite catalyst prepared by the method according to any one of claims 2-8, as an anode catalyst in a direct methanol fuel cell.

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