Boosting Alkaline Hydrogen Evolution by Creating Atomic-Scale Pair Cocatalytic Sites in Single-Phase Single-Atom-Ruthenium-Incorporated Cobalt Oxide
Fei-Fei Zhang, Shaohuan Hong, Ruixi Qiao, Wei‐Hsiang Huang, Zheng Tang, Jiayi Tang, Chih‐Wen Pao, Min‐Hsin Yeh, Jie Dai, Yu Chen, Jun Lü, Zhiwei Hu, Feng Gong, Yinlong Zhu, Huanting Wang
Abstract
Compared with acidic environments, promoting the water dissociation process is crucial for speeding up hydrogen evolution reaction (HER) kinetics in alkaline electrolyte. Although the construction of heterostructured electrocatalysts by hybridizing noble metals with metal (hydr)oxides has been reported as a feasible approach to achieve high performance, the high cost, complicated fabrication process, and unsatisfactory mass activity limit their large-scale applications. Herein, we report a single-phase HER electrocatalyst composed of single-atom ruthenium (Ru) incorporated into a cobalt oxide spine structure (denoted as Ru SA/Co 3 O 4 ), which possesses exceptional HER performance in alkaline media via unusual atomic-scale Ru–Co pair sites. In particular, Ru SA/Co 3 O 4 exhibits a very low overpotential of 44 mV at 10 mA cm –2 and an outstanding mass activity of 4700 mA mg –1 at 50 mV overpotential, superior to those of commercial Pt/C, Ru nanoparticles supported on Co 3 O 4 (denoted as Ru NP/Co 3 O 4 ) and other reported Ru-based electrocatalysts. With insights from theoretical calculations, the synergistic interactions between Ru and Co pair active sites in Ru SA/Co 3 O 4 are revealed to catalyze diverse fundamental steps of the alkaline HER; i.e., the Ru sites can effectively accelerate water adsorption/dissociation and OH – desorption, whereas the Co sites are favorable for H* adsorption and H 2 evolution.