Control Over Nitrogen Dopant Sites in Palladium Metallene for Manipulating Catalytic Activity and Stability in the Oxygen Reduction Reaction

Abstract

AbstractDoping light elements in Pt‐group metals is an effective approach toward improving their catalytic properties for oxygen reduction reaction (ORR). However, it is challenging to control dopant sites and to establish the correlation between the doping site and the catalytic property. In this paper, this success is demonstrated in controlling N doping sites in Pd metallene to manipulate electrocatalytic properties toward ORR. A Pd metallene sample with N dopant predominantly located at the atomic vacancy site (V‐N‐Pd metallene) exhibits two times higher mass activity in ORR than a Pd metallene sample with N dopant mainly occupied the interstitial site (I‐N‐Pd metallene). However, the I‐N‐Pd metallene shows improved durability than the V‐N‐Pd metallene, with only a 4 mV decay in half‐wave potential after 20 000 cycles. Computational calculation results reveal that the significantly enhanced ORR activity of V‐N‐Pd metallene arises from the atomic vacancy‐doped N, which modulates the electronic structure of Pd metallene to weaken the adsorption energy of intermediate O* species. This work provides guidelines for manipulating catalytic properties by controlling the doping sites of light elements in metal nanostructures.