Advanced Cathode Structure for Oxygen Reduction in PEM Fuel Cells

60774 In order to be commercially competitive, Proton Exchange Membrane (PEM) fuel cells have to meet an acceptable level of performance and cost targets for building applications. Most fuel cell performance losses occur at the cathode oxygen reduction reaction (ORR). Improvements in cathode performance are needed in order to increase fuel cell efficiency and reduce stack cost. This project will develop high performance PEM fuel cell cathode structures that will provide more than a three-fold increase in density (at 0.8V) compared to present state-of-the-art Pt-based cathodes. In Phase I, the PEM fuel cell cathode was improved by enhancing proton conduction and adding oxygen flux agents to the catalyst layer. A gain of approximately 15% in power density was obtained when the local environment around the Pt catalyst was modified. Phase II will examine the fundamental activity of the catalyst using a new understanding of the oxygen reduction reaction and will incorporate the catalyst into an improved cathode structure. Also, candidate proton and oxygen flux agents will be optimized, and a nano-scale platinum electrocatalyst will be developed. Commercial Applications and Other Benefits as described by the awardee: The technology should reduce the cost of PEM fuel cells and accelerate the commercialization of PEM for many power generation including portable devices, transportation, distributed generation, and on-site power units for buildings.