Fuel cell electrocatalyst and preparation method and application thereof

Abstract

The invention discloses a fuel cell electrocatalyst and a preparation method and application thereof. The fuel cell electrocatalyst comprises a metal nitrogen-carbon carrier material, platinum precursors are adsorbed to micropores of the metal nitrogen-carbon carrier material, and platinum reduced through an electrochemical reduction method and metal in a carrier form an alloy. The preparation method of the catalyst comprises the following steps: (1) preparing a metal nitrogen-carbon carrier; (2) preparing a catalyst precursor; and (3) platinum reduced by an electrochemical reduction method and the transition metal in the carrier forming an alloy. According to the catalyst, metal nitrogen carbon is used as a carrier to adsorb platinum salt, the particle size of platinum particles is limited through the confinement effect of pore channels, transition metal contained in the carrier and Pt form an alloy, the Pt loading capacity can be reduced, the Pt utilization rate can be increased, thepreparation process is simple, and a product has excellent oxygen reduction activity and can be applied to proton exchange membrane fuel cells.

Description

technical field [0001] The present invention relates to an electrocatalyst and its preparation method and application, more specifically, to a fuel cell electrocatalyst and its preparation method and application. Background technique [0002] The commercially widely used electrocatalysts for proton exchange membrane fuel cells are still Pt / C catalysts. However, platinum resources are scarce and expensive, which seriously hinders the development of fuel cells. Therefore, reducing the amount of precious metal platinum and finding cheap substitutes has become an urgent problem to be solved. The researchers found that Pt-M (M is usually Ti, Cr, Mn, Fe, Co, Ni) alloy catalysts can improve the activity and stability of the catalyst. Among the preparation methods of alloy catalysts, the chemical reduction method is a relatively common method. Usually, after the precursor of the catalyst is mixed with the carrier evenly, a reducing agent is added or the precursor is reduced by hig...

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Problems solved by technology

Among the preparation methods of alloy catalysts, the chemical reduction method is a relatively common method. Usually, after the precursor of the catalyst is mixed with the carrier evenly, a reducing agent is added or the precursor is reduced by high-temperature roasting in a reducing atmosphere to obtain an alloy catalyst. However, the steps of the chemical reduction method are complicated and the synthesis time is long, and the particle size of the formed alloy particles is difficult to control.

The microwave-assisted ethylene glycol reduction method takes advantage of the advantages of rapid and uniform microwave heating, and can synthesize alloy catalysts relatively quickly. However, the high heat generated by microwave heating can easily lead to particle agglomeration, and there are requirements for the amount of precursors and carriers used. , such as too many carriers can easily cause an explosion

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