Carbon alloy catalysts for polymer electrolyte fuel cells: Exploration of materials and understanding of mechanisms

Abstract

The launch of the fuel cell vehicle (FCV) in December 2014 has moved our society into the era of hydrogen energy. Expectations for, and demands on, this technology will first increase steadily and then explosively. Owing to the scarcity of available natural resources and considering costs, the development of cathodes using non-platinum catalysts is an important issue to be addressed for the stable and secure provision of FCVs. We have been developing carbon alloy catalysts, such as nanoshell-containing carbon and boron nitrogen (BN)-doped carbon catalysts, where catalytic activities originate from the carbon surface and not from surface metal complexes. First, we discuss the discovery of carbon materials exhibiting electrocatalytic activity followed by their application to ORR. Second, we provide experimental evidence for ORR activity originating from warped graphitic layers. Next, we describe useful methods to obtain highly active carbon alloy catalysts. Finally, we report a notable single cell performance of 0.65W/cm2 using air as the oxidant.