This Small Business Innovation Research (SBIR) Phase II project addresses the need in the marketplace for fuel cells with improved durability. Polymer electrolyte membrane (PEM) fuel cells offer a potential environmentally friendly source of power, but performance improvements are required before costs justify more widespread adoption of this technology. Catalyst deactivation limits the lifetime of commercial PEM fuel cells, as the catalyst support is subject to oxidation and the active metal component, typically containing platinum, sinters during use. This Phase II project addresses both of these problems. Through a combination of new technologies from the ceramics, electronics, and catalyst industries, the feasibility of producing new support materials that are much more resistant to degradation has earlier been demonstrated. Accelerated aging studies have shown dramatic increases in catalyst lifetime, as much as tenfold. Building on these successes, the goals of this Phase II project are development of an optimized process for preparation of this new catalyst system and the production of prototype commercial fuel cell power packs with this new catalyst system. These prototype devices will be tested to demonstrate if the improvements shown in accelerated aging studies translate into longer lifetimes in commercial products. The broader/commercial impact of this project complements the work reported by others in developing fuel cell catalyst systems with higher activity. Fuel cell systems that combine catalysts with high activity and long lifetime lead to the best overall economics. Fuel cell powered systems also have environmental advantages. The use of fuel cells to generate power leads to a significant reduction in greenhouse gas emissions if they replace systems powered by internal combustion engines. Reductions in emissions as high as 25% have been achieved when fuel cell power supplies replace internal combustion powered systems. The technology to be developed can be used in other applications where attack of a carbon substrate under oxidizing conditions leads to degradation which occurs not only in a variety of catalyst applications but also in electrodes for battery applications