Asymmetric Bond Delta‐Polarization at the Interfacial Se─Ru─O Bridge for Efficient pH‐Robust Water Electrolysis
Ya Chen, Yaoda Liu, Lei Li, Thangavel Sakthive, Zhixin Guo, Zhengfei Dai
Abstract
Abstract The rationalization of pH‐robust catalysis is highly desired but challengeable for overall water electrolysis (WE). It requests a metal active site that can make an efficient adaption with both cathodic hydrogen and anodic oxygen evolution reactions (HER/OER). Herein, a RuO 2‐x /RuSe 2 heterostructure electrocatalyst is profiled with interfacial Se─Ru─O bridge for the pH‐robust water splitting studies. An asymmetric bond delta‐polarization (Δp) is found at the interfacial Se─Ru─O bridge, including the Δp > 0 at the Ru─O part and Δp < 0 at the Ru─Se side by both experiment and calculation results. The enlarged Ru─O bond polarizability (Δp > 0) can in principle trigger the lattice oxygen mediated (LOM) pathway for OER; meanwhile, the reduced Ru─Se bond polarizability can benefit the HER due to the strengthened d‐p band hybridization. Resultantly, the heterostructure can deliver ultralow overpotentials of 25/10 mV for Pt‐beyond HER and 210/255 mV for OER at 10 mA cm −2 in acidic/alkaline media, respectively. In especial, the acidic overall WE can be stably operated for 200 h with a low cell voltage of 1.478 V at 10 mA cm −2 . This research clarifies the asymmetric bond polarization as the criterion for the rational design of efficient WE catalysts.