Mesoporous Non-carbon Catalyst Supports for PEMFC

Proton exchange membrane fuel cells (PEMFC) produce electrical energy from fuels such as hydrogen, with high power density, high efficiency, and low to zero emissions. Important issues that hinder the widespread adoption of PEMFC are low cell endurance and catalyst degradation that results from continuous use. Conventionally, a platinum catalyst is supported on carbon-based supports; the corrosion of carbon support materials is an important reason for catalyst failure with time. Alternate support materials are needed to eliminate failures caused by catalyst support corrosion. The non-carbon materials to be used as a catalyst support must have high surface area, increased dispersion of Pt, high corrosion resistance at low and high temperatures, low solubility in acidic or alkaline media, high electrochemical stability under PEMFC operating conditions, and high conductivity. Transition metal carbides are promising alternatives to carbon as catalyst supports because of their excellent mechanical and chemical stability, resistance to corrosion under reaction conditions, and electrical conductivity. Boron carbide is an attractive material for this purpose because beyond being chemically inert to acids and alkalis, thermally robust, mechanically strong and electrically conducting, it can promote catalytic activity of Pt through synergistic effects. CertainTech will use a nano-casting route to produce mesoporous boron carbide supports. The resultant product will have a very high specific surface area, well-ordered pore structures, and narrowly distributed pore sizes, all of which will aid the even dispersion of platinum for fuel cell applications. The catalytic properties of the Pt-impregnated boron carbide mesoporous support will also be studied.