Preparation method of nitrogen-doped graphene aerogel supported non-precious metal oxygen reduction catalyst

Abstract

The invention provides a preparation method of a nitrogen-doped graphene aerogel supported non-precious metal oxygen reduction catalyst. The method comprises the following steps: stirring a mixed solution of organic amine and aldehyde for 0.5-2 hours at the temperature of 50-90 DEG C, adding graphene oxide and a non-precious salt solution, stirring for 1-24 hours at the temperature of 60-99 DEG C to obtain organogel, performing freezing or supercritical drying, heating to 500-1000 DEG C under protection of inert gas, preserving heat for 1-6 hours, and naturally cooling to room temperature, thereby obtaining the nitrogen-doped graphene aerogel supported non-precious metal oxygen reduction catalyst. The preparation method of the nitrogen-doped graphene aerogel supported non-precious metal oxygen reduction catalyst is simple, the production can be easily expanded, the cost is low, the oxygen reduction catalysis activity is high, and the commercial popularization is facilitated.

Description

technical field [0001] The invention belongs to the field of graphene catalytic materials, in particular to the preparation and application of a nitrogen-doped graphene airgel-loaded non-noble metal oxygen reduction catalyst. Background technique [0002] Oxygen reduction reaction, as the positive electrode reaction of fuel cells and metal-air batteries, has always been a hot spot in electrochemical research. Oxygen has a slow reaction rate, so catalysts are needed. Traditional catalysts are mainly Pt-based noble metals, which have poor stability and high production costs, and are not suitable for commercial promotion. Therefore, it is particularly important to develop a cheap, efficient, stable, and large-scale production of non-noble metal catalysts to replace Pt-based noble metal catalysts. [0003] Graphene is a two-dimensional honeycomb carbon material with a thickness of one atomic layer. It has the characteristics of high specific surface area and high conductivity. ...

AI Technical Summary

Problems solved by technology

[0004] Nitrogen-doped graphene-supported non-precious metal materials are used as oxygen reduction catalysts, which have good oxygen reduction catalytic performance. Chinese patents CN103599805A and CN103611555A mix graphene oxide solution, non-noble metal salt solution and nitrogen-containing organic small molecules, evaporate to dryness, and then The non-noble metal oxygen reduction catalyst supported by nitrogen-doped graphene was obtained by high-temperature heat treatment, which showed good oxygen reduction catalytic activity. However, the graphene layer has π-π interaction, which is easy to reunite during use. And positively charged non-noble metal ions can further promote the agglomeration of negatively charged graphene sheets, making the specific surface area of ​​the composite much smaller than the theoretical specific surface area of ​​graphene, resulting in low utilization of oxygen reduction active sites.

At present, the method to solve graphene aggregation is mainly to make graphene into a three-dimensional gel. Chinese patent CN102849731A uses a mixed solution of graphene oxide and organic amine as a hydrothermal reaction mother liquor to synthesize nitrogen-doped graphene hydrogel. Graphene and nitrogen-containing compounds were used as raw materials to hydrothermally synthesize nitrogen-doped graphene hydrogel, and then heat-treated under the protection of an inert atmosphere to obtain nitrogen-doped graphene airgel. CN103721736A mixed solution of graphene oxide and organic iron compound Transfer to a high-pressure reactor for hydrothermal reaction to obtain an iron-containing graphene hydrogel, and then treat it at a high temperature under an ammonia atmosphere to obtain a nitrogen-doped graphene-supported iron catalyst. The above-mentioned preparation of nitrogen-doped graphene gel involves to the hydrothermal method, and the hydrothermal reaction requires high equipment and low output, which is not conducive to large-scale industrial production

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