In situ copper faceting enables efficient CO2/CO electrolysis
Kaili Yao, Jun Li, Adnan Ozden, Haibin Wang, Ning Sun, Pengyu Liu, Wen Zhong, Wei Zhou, Jieshu Zhou, Xi Wang, Hanqi Liu, Yongchang Liu, Songhua Chen, Yongfeng Hu, Ziyun Wang, David Sinton, Hongyan Liang
Abstract
Abstract The copper (Cu)-catalyzed electrochemical CO 2 reduction provides a route for the synthesis of multicarbon (C 2+ ) products. However, the thermodynamically favorable Cu surface (i.e. Cu(111)) energetically favors single-carbon production, leading to low energy efficiency and low production rates for C 2+ products. Here we introduce in situ copper faceting from electrochemical reduction to enable preferential exposure of Cu(100) facets. During the precatalyst evolution, a phosphate ligand slows the reduction of Cu and assists the generation and co-adsorption of CO and hydroxide ions, steering the surface reconstruction to Cu (100). The resulting Cu catalyst enables current densities of > 500 mA cm −2 and Faradaic efficiencies of >83% towards C 2+ products from both CO 2 reduction and CO reduction. When run at 500 mA cm −2 for 150 hours, the catalyst maintains a 37% full-cell energy efficiency and a 95% single-pass carbon efficiency throughout.