Trace Ionic Liquid‐Assisted Orientational Growth of Cu<sub>2</sub>O (110) Facets Promote CO<sub>2</sub> Electroreduction to C<sub>2</sub> Products
Wenhang Wang, Hui Ning, Xiang Fei, Xiaoshan Wang, Zhengguang Ma, Zhenmei Jiao, Yani Wang, Noritatsu Tsubaki, Mingbo Wu
Abstract
Abstract Cu 2 O has great advantages for CO 2 electroreduction to C 2 products, of which the activity and selectivity are closely related to its crystal facets. In this work, density functional theory calculation indicated that the (110) facets of Cu 2 O had a lower energy barrier for the C−C coupling compared to the (100) and (111) facets. Therefore, Cu 2 O(110) facets were successfully synthesized with the assistance of trace amounts of the ionic liquid 1‐butyl‐3‐methylimidazolium ([Bmim]BF 4 ) by a sample wet‐chemical method. A high faradaic efficiency of 71.1 % and a large current density of 265.1 mA cm −2 toward C 2 H 4 and C 2 H 5 OH were achieved at −1.1 V (vs. reversible hydrogen electrode) in a flow cell. The in situ and electrochemical analysis indicated that it possessed the synergy effects of strong adsorption of *CO 2 and *CO, large active area, and excellent conductivity. This study provided a new way to enhance the C 2 selectivity of CO 2 electroreduction on Cu 2 O by crystal structure engineering.