Geometric Modulation of Local CO Flux in Ag@Cu<sub>2</sub>O Nanoreactors for Steering the CO<sub>2</sub>RR Pathway toward High‐Efficacy Methane Production
Likun Xiong, Xiang Zhang, Ling Chen, Zhao Deng, Sheng Han, Yufeng Chen, Jun Zhong, Hao Sun, Yuebin Lian, Baiyu Yang, Xuzhou Yuan, Hui Yu, Yu Liu, Xiaoqin Yang, Jun Guo, Mark H. Rümmeli, Yan Jiao, Yang Peng
Abstract
Abstract The electroreduction of carbon dioxide (CO 2 RR) to CH 4 stands as one of the promising paths for resourceful CO 2 utilization in meeting the imminent “carbon‐neutral” goal of the near future. Yet, limited success has been witnessed in the development of high‐efficiency catalysts imparting satisfactory methane selectivity at a commercially viable current density. Herein, a unique category of CO 2 RR catalysts is fabricated with the yolk–shell nanocell structure, comprising an Ag core and a Cu 2 O shell that resembles the tandem nanoreactor. By fixing the Ag core and tuning the Cu 2 O envelope size, the CO flux arriving at the oxide‐derived Cu shell can be regulated, which further modulates the *CO coverage and *H adsorption at the Cu surface, consequently steering the CO 2 RR pathway. Density functional theory simulations show that lower CO coverage favors methane formation via stabilizing the intermediate *CHO. As a result, the best catalyst in the flow cell shows a high CH 4 Faraday efficiency of 74 ± 2% and partial current density of 178 ± 5 mA cm − 2 at −1.2 V RHE , ranking above the state‐of‐the‐art catalysts reported today for methane production. These findings mark the significance of precision synthesis in tailoring the catalyst geometry for achieving desired CO 2 RR performance.