(Invited) Catalysts for Fuel Cells

Abstract

The progress in platinum-based catalysts with the goal of improving their activity and durability in a proton exchange membrane fuel cell will be presented. The studies of the oxygen reduction reaction on well-defined surfaces have guided the approach to design of the real world nanostructured catalysts. Insights from single crystalline systems and thin film surfaces have yielded atomically precise information related to surface structure and alloying with other metals in the quest to improve their intrinsic catalytic activity. These experimental efforts are also producing information necessary for the design of catalysts with enhancing stability. Atomic level control of the positioning of elements within catalyst structure enables the design of shapes and surfaces that mimic the key descriptors discovered through research on well-defined surfaces. The meticulous characterization of nanoscale materials using extremely high-purity conditions and cutting-edge techniques provides greater understanding of their performance and degradation pathways. This knowledge enables implementation of these materials in membrane electrode assemblies (MEA) for demonstration of targeted performance in a fuel cell vehicle. The catalyst, its support, water, ionomer, and gaseous reactants create challenging environment to control and engineer at the level that would be capable to address all technical targets that are necessary for wide deployment of this technology. The transition from high-purity liquid electrolytes into MEA still needs to be addressed before stepping into mass production of fuel cell stacks. The overall research strategy presented here exhibits the merits of a continuous pipeline from fundamental to applied research in the development of fuel cell technology.