Single-atom surface anchoring strategy via atomic layer deposition to achieve dual catalysts with remarkable electrochemical performance

Abstract

Pt-Ir catalysts have been widely applied in unitized regenerative fuel cells due to their great activity for the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). However, the application of noble metals is seriously hindered by their high cost and low abundance. To reduce the noble metals loading and catalyst cost, the atomic layer deposition is applied to selectively surface anchoring of Ir single atoms (SA) on Pt nanoparticles (NP). With the formation of SA-NP composite structure, the Ir_SA-Pt_NP catalyst exhibits significantly improved performance, achieving 2.0- and 90-times mass activity by comparison with the benchmark Pt/C catalyst for the ORR and OER, respectively. Density functional theory calculations indicate that the SA-NP cooperation synergy endows the Ir_SA-Pt_NP catalyst to surpass the bifunctional catalytic activity limit of Pt-Ir NPs. This work provides a novel strategy for the construction of high-performing dual catalyst through designing the single atom anchoring on NPs.