Engineering CO<sub>Bridge</sub> Adsorption in Cu<sub>2</sub>O-TiO<sub>2</sub> Heterojunction Catalyst for Selective Electrochemical CO<sub>2</sub> Reduction to Ethanol
Huiying Zhang, Yanfei Sun, Jinrui Wang, Xueying Gao, Zheng Tang, Shuyuan Li, Zishan Hou, Xiaojun Wang, Kaiqi Nie, Jiangzhou Xie, Zhiyu Yang, Yi‐Ming Yan
Abstract
Selective electroreduction of carbon dioxide (CO 2 ) into multicarbon products using copper-based catalysts, primarily governed by CO adsorption configurations such as atop-adsorbed *CO (CO atop ) and bridge-adsorbed *CO (CO bridge ), is a promising strategy for converting greenhouse gases into valuable chemicals and fuels. However, the production of ethanol (C 2 H 5 OH), a crucial chemical feedstock, is significantly limited by weak CO bridge adsorption on copper-based catalysts. Herein, a Cu 2 O-TiO 2 heterostructure catalyst was designed to adjust the CO adsorption configurations for promoting the selectivity of ethanol. At an applied potential of −0.7 V vs RHE, Cu 2 O-TiO 2 demonstrated a 5.1-fold increase in the Faradaic efficiency (FE) for C 2 H 5 OH (27.13%) compared to that of Cu 2 O (5.2%). Experimental and theoretical calculation results verified the strong electronic interactions between Cu 2 O and TiO 2 in Cu 2 O-TiO 2, resulting in an increase in the valence state of Ti and consequently enhancing the oxophilicity of TiO 2 . Moreover, carbon monoxide temperature-programmed desorption (CO-TPD) results, in situ Raman spectra, and DFT calculations revealed a more robust CO bridge adsorption on the Cu 2 O-TiO 2 surface than on Cu 2 O due to the improved oxophilicity of TiO 2, which is responding for the better ethanol selectivity of the electrocatalytic CO 2 reduction reaction (CO 2 RR). This work offers original insights into the design of electrocatalysts for the selective production of ethanol from the CO 2 RR by engineering CO adsorption configurations.