Copper-indium hydroxides derived electrocatalysts with tunable compositions for electrochemical CO2 reduction

Bimetallic Cu-In hybrid electrocatalysts are promising noble metal-free catalysts for selective electrochemical CO2 reduction reaction (ECO2RR). Most reports show Cu-In catalysts are selective towards COevolution. However, few show similarly high selectivity towards formate. Herein we fabricated composition tunable Cu-In hydroxides (CuxIny-OH) by the hydrothermal method and studied their composition effect on electrochemical CO2 reduction in detail. Wefound that the selectivity of CO2 reduction products shifted from CO to formate when the content of In increased in the CuxIny-OH electrocatalysts. The Cu rich electrocatalyst mostly produced CO, which could achieve a Faradaic efficiency (FE) to 75.8% at -0.59 V vs. RHE (Cu76In24 based electrocatalysts). In comparison, the In rich electrocatalysts selectively produced formate, which possessed the FE of formate up to 85% at -1.01 V vs. RHE. Our work systematically illustrates the composition effect on hybrid catalysts, and provides insights into the design of highly selective catalysts for ECO2RR. (C) 2021 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by ELSEVIER B.V. and Science Press. All rights reserved.