Stabilizing Ru Single Atoms on Asymmetric La/Co<sub>3</sub>O<sub>4</sub> Supports with Strong Metal–Support Interaction for Efficient Acidic Water Oxidation
Conghui Li, Cheng‐Zong Yuan, Chenliang Zhou, Xuan Yang, Ruilong Xu, Fuling Wu, Xin Lei, Lingxian Wang, Xiaomeng Zhang, Kwun Nam Hui, Shufeng Ye, Yunfa Chen
Abstract
Exploring highly efficient and stable single-atom electrocatalysts for the oxygen evolution reaction (OER) is urgent for cost-effective hydrogen production by a proton exchange membrane water electrolyzer, but their stability is limited owing to the harsh corrosive and oxidative environments. Herein, we propose the synthesis of stable Ru single atoms (SAs) on the La-doped Co 3 O 4 surface (Ru@La/Co 3 O 4 -20) via a strong metal–support interaction (SMSI), which exhibits a low overpotential at 10 mA cm –2 (η 10: 244 mV) and a stability of 30 h (decay rate: 3.7 mV h –1 ) at 10 mA cm –2, outperforming Ru SAs on the Co 3 O 4 surface (Ru@Co 3 O 4 ) (η 10: 295 mV; decay rate: 12.7 mV h –1 ) and benchmark RuO 2 . Experiments and density functional theory calculations demonstrate that electron transfer occurs from Ru SAs to asymmetric La/Co 3 O 4 supports through bridge O atoms, strengthening the SMSI. Compared to Ru@Co 3 O 4, the stronger SMSI between Ru SAs and asymmetric La/Co 3 O 4 supports could help to adjust the Ru 4d and 2p band center’s location, which optimizes the adsorption of O intermediates and weakens Ru–O covalency, thus boosting the acidic OER activity and stability of Ru@La/Co 3 O 4 -20.