SAD–GLAD Pt–Ni@Ni Nanorods as Highly\nActive Oxygen Reduction Reaction Electrocatalysts

Abstract

Vertically\naligned catalysts comprised of platinum–nickel\nthin films on nickel nanorods (designated as Pt–Ni@Ni-NR) with\nvarying ratios of Pt to Ni in the thin film were prepared by magnetron\nsputtering and evaluated for their oxygen reduction reaction (ORR)\nactivity. A glancing angle deposition (GLAD) technique was used to\nfabricate the Ni nanorods (NRs) and a small angle deposition technique\nfor growth of a thin conformal coating of Pt–Ni on the Ni-NRs.\nThe Pt–Ni@Ni-NR structures were deposited on glassy carbon\nfor evaluation of their ORR activity in an aqueous acidic electrolyte\nusing the rotating disk electrode technique. The Pt–Ni@Ni-NR\ncatalysts showed superior area-specific and mass activities for ORR\ncompared to those of Pt–Ni alloy nanorod catalysts prepared\nusing the GLAD technique and compared to those of conventional large-surface\narea Pt and Pt–Ni alloy nanoparticle catalysts.