Synergy of rare earth single atoms and Pt nanoclusters@N-doped carbon for improved alkaline hydrogen evolution

Abstract

The sluggish water dissociation kinetics and low stability of Pt nanocluster (Pt NC )-based electrocatalysts severely restricts the alkaline hydrogen evolution reaction (HER). By integrating the electron-buffer functionality of rare earth single atoms (RE SAs : Ce, Pr, Sm, Gd) dispersed on N-doped carbon (NDC) with Pt NCs , we report a novel catalyst Pt NCs -RE SAs @NDC. The RE→Pt electron redistribution through the constructed Pt⌒N⌒Pr interfacial electron bridge: i) makes Pt NCs electron-rich and RE SAs electron-deficient, which favors adsorption of H ads and OH ads , respectively, ii) increases covalency of Pt-N bond improves stability by reinforcing Pt NCs -substrate interaction. Significantly boosted high mass activity (25.4 A•mg Pt -1 at an overpotential of 100 mV), only 10% Pt loading (of commercial Pt/C), and outstanding operational stability (runs stably at 500 mA•cm -2 for 500 h in an alkaline anion exchange membrane water electrolyzer) are realized by integrating the unique electronic features of RE SAs, e.g., Pt NCs -Pr SAs @NDC. These advancements demonstrate great potential of RE SAs for high-efficient HER.