High-activity carbon-supported platinum catalyst for low-platinum-loading proton exchange membrane fuel cell and preparation method thereof

Abstract

The invention discloses a high-activity carbon-supported platinum catalyst for low-platinum-loading proton exchange membrane fuel cell and a preparation method thereof. The method comprises the following steps: (1) purifying carbon powder; (2) preparing carbon ink, namely mixing carbon powder, isopropanol, deionized water and zirconium oxide balls, and performing ball milling to obtain the carbonink; (3) preparing an ultrathin carbon powder layer, namely dripping carbon ink into a flat-bottom vessel filled with deionized water, uniformly spreading the carbon particles on the water surface, and performing drying to form the ultrathin carbon powder layer; and (4) preparing the high-activity carbon-supported platinum catalyst, namely preparing the high-activity carbon-supported platinum catalyst by taking the ultrathin carbon powder layer as a substrate and sputtering platinum through magnetron sputtering. The Pt average particle size of the prepared high-activity carbon-supported platinum catalyst is 3 nm, distribution is uniform, the particle size range is 2.5-3.5 nm, and the size distribution range is narrow. The carbon-supported platinum catalyst can be applied to a cathode catalyst layer of a proton exchange membrane fuel cell, and compared with commercial Pt / C, the power density of the cell is greatly improved.

Description

technical field [0001] The invention belongs to the technical field of proton exchange membrane fuel cells, and in particular relates to a highly active carbon-supported platinum type catalyst for low platinum loading proton exchange membrane fuel cells and a preparation method thereof. Background technique [0002] There have been a lot of research reports on the preparation methods of carbon-supported Pt catalysts, mainly including impregnation method, colloid method, microemulsion method, electrochemical deposition method, ion exchange method and supercritical fluid method. The traditional preparation methods that are widely used at present are impregnation method and colloid method. The impregnation method is usually to impregnate activated carbon in acid H 2 PtCl 6 In aqueous solution or alkaline [Pt(NH 3 ) 4 ] Cl 2 In the aqueous solution, then use the reducing agent (such as formaldehyde, hydrogen, etc.) to reduce Pt, and finally obtain the carbon-supported Pt cat...

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Problems solved by technology

However, there are strict requirements on solvent, pH value and operating conditions, and it is difficult to control. Adding a protective agent can control the particle size and distribution of Pt particles, which also increases the complexity of the operation and increases the cost.

The above-mentioned methods are all chemical preparation methods. The main disadvantage is that the preparation process is cumbersome, especially the reduction and purification process is complex, and a large amount of chemical waste and high energy consumption will be generated during the reaction process.

The Pt particle size distribution of the Pt / C catalyst prepared by the above method is relatively wide, and the uniformity is average. The power density of the prepared battery is acceptable but there is still room for improvement.

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