Oxidation-Reduction Potential Control for One Step Synthesis of Cu-Pt Core-Shell Nanoparticles

Abstract

Cu-Pt core-shell nanoparticles (NPs) are prospective to reduce the amount of Pt loading in polymer electrolyte fuel cells (PEFCs). In order to synthesize Cu-Pt core-shell NPs, it is necessary to separate reduction processes of Cu and Pt each other or inverse the oxidation-reduction potentials (ORPs) of them. Here, we demonstrate two steps synthesis by galvanic displacement and one step synthesis by ORP control. In the two steps process, Pt hollow NPs were obtained because the inner Cu was not perfectly covered by Pt and leached out. ORP calculation technique was developed, and Cu-Pt core-shell NPs were synthesized with alloy NPs via one step process. The Cu-Pt core-shell NPs showed much higher specific activity than commercial Pt catalyst.