Screening of Oxygen-Reduction-Reaction-Efficient Electrocatalysts Based on Ag–M (M = 3d, 4d, and 5d Transition Metals) Nanoalloys: A Density Functional Theory Study

Abstract

As a result of the high cost and scarcity of Pt and Pt-based materials as electrocatalysts with high oxygen reduction reaction (ORR) performance at the carbon-supported oxygen cathode of polymer electrolyte membrane fuel cells (PEMFCs), we perform a screening of ORR-efficient electrocatalysts based on Ag–M nanoalloys, where M is a 3d, 4d, or 5d transition metal using density functional theory (DFT) methods. We consider atomic oxygen adsorption energy Eads(O) as a descriptor to explore the cheap and ORR-efficient Ag–M(111) (M = 3d, 4d, and 5d transition metals) surfaces in various suballoying configurations compared to the Pt(111) surface. Our calculated results reveal that the Ag-shelled catalysts by subsurface alloying with all 3d, 4d, and 5d transition metals are more stable than pure Ag(111) by analyzing the surface energy and surface segregation energy of Ag–M alloys and consistent with Pt–M alloys suballoying with 3d transition metals. Moreover, the d-band center of the same Ag–M alloy with different...