Oxygen reduction catalyst based on nitrogen-doped graphene aerogel and preparation method therefor

Abstract

The invention discloses an oxygen reduction catalyst based on nitrogen-doped graphene aerogel and a preparation method therefor. The oxygen reduction catalyst is mainly a graphene aerogel with a gradient pore structure, and the aerogel contains a nitrogen-containing functional group. The preparation method comprises the following steps of adding ammonia water into a graphene hydrogel to freeze dry, so that the graphene aerogel is obtained, and further treating the graphene aerogel with high-temperature ammonia gas, nitrogen element is heavily doped after two steps, so that the nitrogen-doped graphene aerogel is synthesized. The graphene aerogel provided by the preparation method has a developed pore structure and contributes to the transport of reactants such as oxygen, hydrogen ions and water. According to the oxygen reduction catalyst based on nitrogen-doped graphene aerogel and the preparation method therefor, the nitrogen-containing functional group is further introduced into the aerogel by means of a high-temperature ammonia gas treatment, so that conductivity and catalytic activity of the catalyst are improved. Compared with a traditional platinum-based catalyst, the nitrogen-doped graphene aerogel has comparable ORR catalytic performance, the cost is greatly reduced, and good application prospects are achieved.

Description

technical field [0001] The patent relates to an oxygen reduction catalyst and a preparation method thereof, in particular to an oxygen reduction catalyst based on nitrogen-doped graphene airgel and a preparation method thereof. Background technique [0002] Fuel cells are a green energy technology that uses the oxidation reaction of fuel and the reduction reaction of oxidant to generate electricity. Among them, oxygen has the advantages of wide sources and mild reaction conditions, and is an ideal oxidant for fuel cell technology. The reduction reaction (Oxygen Reduction Reaction, ORR) of oxygen at the cathode of the fuel cell cannot proceed spontaneously, and a catalyst is required for catalysis. Traditional ORR catalysts use precious metals such as platinum and platinum alloys, but platinum-based catalysts have problems such as CO poisoning, poor long-term stability, and high cost. Therefore, it is urgent to study new materials that can replace platinum-based ORR catalyst...

AI Technical Summary

Problems solved by technology

Recently, low-cost carbon-based catalysts have received more and more attention, such as activated carbon, activated carbon fibers, carbon nanotubes, polypyrrole / carbon black mixtures, etc., especially hybrid graphene-based materials, due to their excellent The advantages of electrical conductivity and abundant catalytic sites have been gradually studied by scientists since 2013, but so far there have been no reports of graphene aerogels doped with nitrogen for oxygen catalytic processes

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