Proton high polymer modified fuel cell catalyst using carbon as carrier and its preparation

Abstract

The invention relates to a fuel battery catalyst which uses proton-conductive polymer to decorate carbon as carrier. Wherein, the carbon carrier of catalyst is decorated by proton-conductive polymer; the invention has the advantages that (1) the expensive metal particle can be anchored on the surface of carrier, to improve the utilization of catalyst; (2) the expensive metal particles can directly contact the polymer to form more three-phase react interfaces to improve the catalyst utilization; (3) the proton polymer used as adhesive can improve the combine force between metal particle and conductive ceramic; (4) the proton polymer is proton conductor, and the composed catalyst has proton conductive function. The relative preparation comprises that preparing the carbon carrier decorated by proton-conductive polymer, then loading catalyst metal particles on its surface, whose average diameter is 2-5nm. And the catalyst can be prepared into fuel battery chip CCM, with better electric output property.

Description

technical field [0001] The invention relates to a catalyst, especially a catalyst used in a fuel cell, which is characterized in that the carrier of the catalyst is carbon modified by a proton-conducting high polymer. The invention also relates to a preparation method of the catalyst. Background technique [0002] As a new type of energy, proton exchange membrane fuel cell (PEM Fuel Cell) has the advantages of low operating temperature, no pollution, high specific power, and rapid start-up. . Fuel cells typically use the precious metal platinum or platinum alloy catalysts. Platinum is a scarce resource and is expensive. Therefore, it is necessary to increase the utilization rate of Pt and reduce the amount of Pt to reduce the cost of fuel cells. At present, people generally use carbon black as a catalyst carrier, because carbon black has a higher specific surface area, which is beneficial to improve the dispersion of metal platinum particles. Changchun Institute of Appl...

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Problems solved by technology

But the utilization ratio of the Pt or Pt alloy catalyst prepared by the above method will not be very high, an important reason is that a large amount of Pt or Pt alloy particles enter in the micropores on the carbon black surface (as figure 1 ), cannot form a three-phase reaction interface with the proton conductor and the reaction gas, thereby reducing the utilization rate of Pt

In addition, since Pt or Pt alloy is directly connected with carbon, it is difficult for proton exchange resin to enter the position between Pt or Pt alloy and carbon during the preparation of membrane electrodes.

On the one hand, this reduces the three-phase reaction zone, on the other hand, due to the lack of bonding, the bonding strength between Pt or Pt alloys and carbon is not high

[0003] At present, there is no report on the use of proton-conducting polymers to modify fuel cell carbon supports as catalysts

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