Adjusting Local CO Confinement in Porous-Shell Ag@Cu Catalysts for Enhancing C–C Coupling toward CO<sub>2</sub> Eletroreduction
Yongzhi Zhong, Xiangdong Kong, Zhimin Song, Yan Liu, Liping Peng, Zhang Lin, Xuan Luo, Jie Zeng, Zhigang Geng
Abstract
Tuning the local confinement of reaction intermediates is of pivotal significance to promote C–C coupling for enhancing the selectivity for multicarbon (C2+) products toward CO2 electroreduction. Herein, we have gained insights into the confinement effect of local CO concentration for enhanced C–C coupling over core–shell Ag@Cu catalysts by tuning the pore diameters within porous Cu shells. During CO2 electroreduction, the core–shell Ag@Cu catalysts with an average pore diameter of 4.9 nm within the Cu shells ([email protected]) exhibited the highest Faradaic efficiency of 73.7% for C2+ products at 300 mA cm–2 among the three Ag@Cu catalysts. Finite-element-method simulations revealed that the pores with a diameter of 4.9 nm in Cu conspicuously enhanced the local CO concentration. On the basis of in situ attenuated total reflection surface-enhanced infrared absorption spectroscopy measurements, [email protected] exhibited the highest surface coverage of adsorbed CO intermediates with a linear adsorption configuration due to the confinement effect, thus facilitating C–C coupling.