A catalyst with ultra-low platinum content for fuel cell and preparation method thereof

Abstract

The invention provides a catalyst with ultra-low platinum content for a fuel cell and a preparation method thereof. After heat treatment of a metal source and oleylamine and trioctylphosphine, a noblemetal salt is added dropwise and dried to form spherical nanoparticles, The nano-particles containing organic phase are loaded on the surface of graphite electrode and the organic phase is removed simultaneously by vacuum pre-sintering reduction. During the electrochemical treatment, copper is deposited on the surface of graphite electrode to form a monoatomic layer of copper. At last, platinum is replaced by potassium chloroplatinate to form a multilayered core-shell structure of transition metal-precious metal-platinum and finally the required catalyst is prepared by carbon loading. A monoatomic layer formed by underpotential deposition of copper is replaced by platinum, The thickness of the platinum layer can be controlled effectively, and the catalytic active sites on the surface of the platinum layer are not affected, so that the catalytic performance is guaranteed, the manufacturing cost of the catalyst is reduced, and the defects that the thickness of the platinum layer and thereduction of the surface active sites are difficult to be controlled by the catalyst with low platinum loading capacity are overcome.

Description

technical field [0001] The invention relates to the field of fuel cell materials, in particular to an ultra-low platinum content catalyst for fuel cells and a preparation method. Background technique [0002] Since traditional fossil fuels are non-renewable and cause serious environmental pollution during use, seeking environmentally friendly renewable energy is a severe task facing mankind in the 21st century. Proton Exchange Membrane Fuel Cell (PEMFC)) uses a polymer membrane as a solid electrolyte, which has the characteristics of high power density, high energy conversion efficiency, low temperature start-up, no pollution, light and small size, etc., and is especially suitable as a mobile power source. [0003] PEMFC is mainly composed of end plates, bipolar plates, membrane electrodes and other components. Membrane electrode is the core component of PEMFC, mainly composed of catalytic layer, gas diffusion layer and proton exchange membrane. Among them, the catalytic ...

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Problems solved by technology

However, the dealloying treatment requires high equipment operation, and it needs to react with acid, which may reduce the surface active sites and reduce the catalyst activity.

[0007] At present, the content of platinum is reduced by simple replacement reaction using non-metal or transition metal as the carrier, but it is difficult to control the thickness of the surface layer at the microscopic level while reducing the content of platinum, and the reduction of surface active sites in dealloying treatment will reduce the catalyst activity.

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