Development of electrocatalysts for solid alkaline fuel cell (SAFC)

It is now widely accepted that the proton exchange membrane fuel cell (PEMFC) concepts can be applied for a rather large range of power production at low temperature, including ambient conditions for some applications. For small power units, the concept of fuel cell with a solid electrolytic membrane can be extended to the alkaline medium. The main condition is to develop an anionic membrane with a sufficient stability and a good electric conductivity. The aim of this paper is to discuss on the development of electrocatalysts (both anodic and cathodic) suitable with their use in a solid alkaline fuel cell working at room temperature. The fuel cell is conceived around a new kind of anionic membrane developed by an industrial partner. The catalysts need to be adapted to this new concepts and working conditions. For oxygen reduction, catalysts containing silver have been prepared and gave encouraging results. For the anodic side, fuels such as methanol or ethylene-glycol have been considered. Platinum-based catalysts have been developed and tested in addition with platinum-free electrocatalysts. The electrocatalytic activity of Pt-Pd catalysts was first evaluated in semi-cell in order to optimize the composition of the electrodes. Then, tests in fuel cells working at room temperature were carried out, and confirm the validity of the solid alkaline fuel cell (SAFC). A power density of 18-20 mW cm(-2) was observed with methanol or ethylene-glycol at 20 degrees C. (c) 2005 Elsevier B.V. All rights reserved.