A tin-based tandem electrocatalyst for CO2 reduction to ethanol with 80% selectivity

Abstract To date, only Cu-based catalysts have been used to generate appreciable C2 chemicals via the electrochemical CO 2 reduction reaction (CO 2 RR). Here we report a Cu-free, Sn-based tandem electrocatalyst consisting of SnS 2 nanosheets and single Sn atoms coordinated with three oxygen atoms on three-dimensional (3D) carbon, which exhibits significant catalytic performance for selective reduction of CO 2 to ethanol with a maximum selectivity of approximately 82.5% at 0.9 V versus the reversible hydrogen electrode (RHE) and more than 70% over a wide electrode potential window from − 0.6 to -1.1 V versus RHE. This new catalyst maintains 97% of its initial activity (with a geometric current density of 17.8 mA·cm − 2 at 0.9 V versus RHE) after 100 hours of reaction. First principles modeling shows that the dual active centers comprising Sn and O atoms that can respectively adsorb *CHO and *CO(OH) intermediates, therefore promoting C-C bond formation through an unprecedented formyl-bicarbonate coupling pathway.