Enhanced CO2 Adsorption Capability for Highly Selective Electroreduction of CO2 to Formate

Abstract

Electrochemical reduction of CO2 (CO2RR) has been regarded as a promising approach to reduce CO2 emission and produce value-added fuels simultaneously. However, the low reaction kinetics, high overpotential for the target products, and the competitive hydrogen evolution reaction significantly limit the performance for CO2RR. Thus, it is desirable to design highly active and selective electrocatalysts to advance the electrocatalytic performance. Herein, we prepared bismuth subcarbonate nanoflowers (BOC NFs) as a highly active and selective electrocatalyst for CO2RR to formate formation. The increased formate selectivity of over 90 % is achieved in a wide potential range with good stability and high energy efficiency. The in situ DRIFTS measurement reveals the strong CO2 adsorption capability of BOC NFs that ensures the good accessibility of CO2 during CO2RR. Also, the abundant active sites and fast charge transfer ability of BOC NFs jointly contribute to the improved catalytic performance to formate formation. The density functional theory calculation further confirms the increased adsorption energy of CO2 and intermediate that enhances the performance for CO2RR to formate on BOC NFs. Overall, this electrocatalyst holds a promising future as a candidate for highly selective and effective CO2RR to formate.