Facile and Stable CuInO 2 Nanoparticles for Efficient Electrochemical CO 2 Reduction.

Searching for electrocatalysts for the electrochemical CO 2 reduction reaction (e-CO 2 RR) with high selectivity and stability remains a significant challenge. In this study, we design a Cu-CuInO 2 composite with stable states of Cu 0 /Cu + by electrochemically depositing indium onto CuCl-decorated Cu foil. The catalyst displays superior selectivity toward the CO product, with a maximal Faraday efficiency of 89% at -0.9 V vs the reversible hydrogen electrode, and maintains impressive stability up to 27 h with a retention rate of >76% in Faraday efficiency. Our systematical characterizations reveal that the catalyst's high performance is attributed to CuInO 2 nanoparticles. First-principles calculations further confirm that CuInO 2 (012) is more conducive to CO generation than Cu(111) under applied potential and presents a higher energy barrier than Cu(111) for the hydrogen evolution reaction. These theoretical predictions are consistent with our experimental observations, suggesting that CuInO 2 nanoparticles offer a facile catalyst with a high selectivity and stability for e-CO 2 RR.