Regenerating Pt–3d–Pt model electrocatalysts through oxidation–reduction cycles monitored at atmospheric pressure

Abstract The interchange between the Pt–Ni–Pt and Ni–Pt–Pt bimetallic configurations in O 2 and H 2 is confirmed experimentally at atmospheric pressure using in situ X-ray absorption spectroscopy (XAS). The subsurface Pt–3d–Pt structure, a desirable configuration as cathode electrocatalysts for PEM fuel cells, is found to be preferred in the reducing environment of H 2 whereas the surface 3d–Pt–Pt configuration is preferred in O 2 . This process has been found to be reversible, providing useful insights into the maintenance and regeneration of the desirable subsurface structure.

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