Improved Fuel Cell Cathode Catalysts Using Combinatorial Methods

72683-The commercialization of polymer electrolyte fuel cells is hindered not only by the high cost of platinum (Pt) electrocatalysts, but also because these catalysts have insufficient activity toward the oxygen reduction reaction (ORR). In a PEM fuel cell that uses state-of-the art cathode Pt catalysts, about 80 % of the overall cell losses is caused by the sluggish kinetics of the ORR, even at Pt loading as high as 4 mg/cm2. Therefore, it is urgently important to develop novel electrocatalysts that are more active than Pt. This project will develop high throughput combinatorial strategies and a mechanistic model to identify new catalyst compositions that will improve the ORR kinetics. In Phase I, highly efficient and multi-function high throughput screening systems, coupled with advanced process robotics, were established. Compared to the commercial pure Pt catalyst, a significant enhancement of electrocatalytic activity was achievd by alloying Pt and Co. Phase II will concentrate on the combinatorial discovery of ternary alloy electrocatalysts of Pt and transition metals and the high throughput screening of synthesized catalysts. An order-of-magnitude improvement of catalytic activity will be demonstrated. Commercial Applications and Other Benefits as described by awardee: A highly efficient oxygen reduction catalyst would be a huge boost to the commercialization of PEM fuel cells for a wide range of applications in transportation, portable power, communications and military markets.