Electrocatalyst Design for an Elevated Temperature Proton Exchange Membrane Direct Ethanol Fuel Cell

Abstract

Ethanol presents several advantages over other alternative fuels. Its volumetric energy density (23.4 MJ/L) is slightly lower than gasoline (33.4 MJ/L), but much better than available with either methanol or hydrogen. If an ethanol is used in a proton exchange membrane (PEM) fuel cell the lowered energy density compared to gasoline in an internal combustion engine can in theory be overcome. This assumes that an electrochemical system can be developed that carries out the complete 12-electron oxidation of ethanol. To reach this goal, new catalyst systems must be developed. It is found that multicomponent catalysts such as platinum tin oxide (Pt/SnO2) and platinum tin oxide titanium dioxide (Pt/SnO2/TiO2) improve the conversion of ethanol to its 12-electron oxidation products. Catalysts of this type can be quickly prepared usingamicrowave-assisted polyol procedure. Elevation of the operating temperature of a PEM fuel cell using the indicated catalysts to 130åC facilities production of CO2 and provides an improved current-voltage response.