Pdx@Pt/C core-shell structure cathode catalyst for fuel cell and preparation method of Pdx@Pt/C core-shell structure cathode catalyst

Abstract

The invention discloses a Pdx@Pt / C core-shell structure cathode catalyst for a fuel cell and a preparation method of the Pdx@Pt / C core-shell structure cathode catalyst. The method comprises the following steps: (1) adding a palladium precursor and a conductive carrier to N,N-dimethyl formamide or ethanol, carrying out ultrasonic mixing, and then adding borane.N,N-diethyl aniline or sodium borohydride, reacting at a room temperature for 0.5-1.5h, carrying out centrifugal washing and vacuum drying and then obtaining a carbon-supported Pd catalyst, namely Pd / C; and (2) ultrasonically dispersing the Pd / C prepared in the step (1) into a formic acid solution with the concentration of 1-5ml formic acid / 20ml water, adding a water solution of a platinum compound at the atomic ratio of Pt to Pd being 1 to 1 or 1 to 2 or 1 to 3, reacting at the room temperature for 2-6h, and carrying out centrifugal washing and vacuum drying to obtain the product. The catalyst with high catalytic activity and stability is prepared by a primary cell reaction principle; the catalyst is lower than a pure Pt catalyst in cost; the preparation method is simple, convenient, mild in condition and easy to operate; and the problem that a high temperature and a surfactant are required for preparation of the core-shell structure catalyst by a conventional chemical reduction method is solved.

Description

technical field [0001] The invention belongs to the field of fuel cell catalysts, in particular to a PdxPt / C core-shell structure fuel cell cathode catalyst and a preparation method thereof. Background technique [0002] The noble metal Pt is currently one of the best catalysts for the fuel cell cathode oxygen reduction reaction. However, the use of pure Pt as a fuel cell cathode catalyst has problems of low performance and poor stability. In addition, as one of the rarest elements on earth, the high cost also greatly limits its commercial application. Although Pt with 3 d Alloys formed by transition metals Fe, Co, Ni, Cu, etc. can improve the performance of fuel cell cathodes to a certain extent, but these 3 d The easy solubility of metals under acidic conditions leads to poor stability of the catalyst as a whole. If it is prepared as a core-shell structure MPt (M represents a single metal or alloy) catalyst, the stability of the catalyst can be improved while improvin...

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Problems solved by technology

Chemical reduction generally requires a higher temperature to ensure the uniform coating of Pt, and surfactants to prevent the aggregation of the generated Pt particles; the method of underpotential deposition of a Cu monolayer and then Pt replacement cannot achieve a full monolayer coating, and The amount prepared is very small, and it is difficult to achieve large-scale preparation

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