Cu-Sn Electrocatalyst Prepared with Chemical Foaming and Electroreduction for Electrochemical CO2 Reduction

Abstract

The conversion of CO2 through the electrochemical reduction reaction (ECO2RR) into chemicals or fuels is regarded as one of the effective ways to decrease atmospheric CO2 concentrations. In this study, a Cu-Sn bimetallic electrocatalyst (ER-SnmCunOx-t/CC) was successfully prepared via a chemical foaming method and electrochemical reduction. SEM showed that ER-Sn1Cu1Ox-500 nanoparticles were uniformly distributed on the carbon cloth, which benefited from foaming. The XPS results demonstrated the synergistic interaction between Cu and Sn and the existence of oxygen vacancies originating from the electroreduction. Due to the above features, ER-Sn1Cu1Ox-500/CC achieved 84.1% FE for HCOOH at −1.1 V vs. RHE, and the corresponding JHCOOH was up to 32.4 mA·cm−2 in the H-type cell. Especially in the flow cell, ER-Sn1Cu1Ox-500/GDE could reach a high JHCOOH of 190 mA·cm−2 at −1.1 V vs. RHE and maintained JHCOOH higher than 100 mA·cm−2 for 24 h with a formic acid selectivity over 70%, indicating both excellent catalytic activity and high HCOOH selectivity. In situ FTIR results revealed that synergism between Cu and Sn could regulate the adsorption of intermediates, thus enhancing the catalytic performance of ER-Sn1Cu1Ox-500 for ECO2RR.