Self-healing Cu single-atom catalyst for high-performance electrocatalytic CO2 methanation
Wanyu Shen, Xiaoping Gao, Qichen Liu, Peng Li, Rui Huang, Yi Tan, Zihan Wang, Yilin Zhang, Fan Zhao, Xin Wang, Shiyu Ji, Xusheng Zheng, Yu Zhang, Yuen Wu, Yu Zhang, Yuen Wu
Abstract
To address the escalating challenge of atmospheric CO2 emissions, this study proposes a self-healing Cu single atom (SA) catalyst design. By partially cleaving Cu-N bonds via hydrogen evolution reaction (HER), coordinatively unsaturated Cu sites form and spontaneously bond with adjacent ZrO2 clusters which are strategically positioned near the Cu SA, creating a hybrid Cu-N/O structure with enhanced performance. In situ Raman and X-ray absorption fine structure (XAFS) measurements confirm the dynamic reconstruction of coordination environment from CuN4 to CuN1O2 under electrochemical conditions. The reconstructed CuN1O2 achieve observed performance for CO2-to-CH4 conversion, reaching a Faradaic efficiency of 87.06 ± 3.22% at −500 mA cm−2 and 80.21 ± 1.01% at −1000 mA cm−2, which are threefold and tenfold higher than those of pristine CuN4. Furthermore, a 25-h stability test with 500 mA cm−2 current density in a membrane electrode assembly (MEA) electrolyzer demonstrates minimal activity decay (< 3%). Density functional theory (DFT) calculations demonstrate that self-healing mechanisms optimize intermediate adsorption and electron distribution. This strategy enables efficient muti-electron transfer processes under industrial conditions, working to improve the stability of single-atom catalysts and develop scalable catalytic systems. Robust Cu single-atom catalysts show promise for CO2 electroreduction but face stability challenges. Here, the authors report a self-healing Cu single-atom catalyst that maintains high performance and stability for CO2-to-CH4 conversion at industrial current densities.