Proton exchange membrane fuel cells (PEMFC) become increasingly attractive because of their high conversion efficiency, low pollution, lightweight, high power density, and a wide range of applications from power sources in automobiles and space shuttles to power grids for buildings and factories. We have developed a promising strategy for nano-engineering the size, shape, composition and structural properties of multimetallic nanoparticles (e.g., AuPt, PtNi, PtCo, PtVFe, PtNiFe, PtNiCo, etc.) as active and stable clectrocatalysts for ORR in fuel cell cathode reaction. For the trimetallic Pt-based catalysts prepared by our nano-engineered synthesis and processing,5 the high electrocatalytic activity of the catalysts for ORR is a result of the introduction of a second or third metal with smaller atomic size than platinum, which produces a combination of reduction of the Pt-Pt distance, formation of metal-oxygen bond and adsorption of hydroxide groups, and the modification of the d-band center. In this report, we describe some recent results from an investigation of the structural correlation of electrocatalytic activities of Pt-based ternary alloy catalysts for ORR.
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