Tuning adsorption strength of CO2 and its intermediates on tin oxide-based electrocatalyst for efficient CO2 reduction towards carbonaceous products

Abstract The catalytic performance of electrocatalyst on carbon dioxide reduction reaction (CO2RR) heavily depends on the adsorption strength of intermediates and electronic structure. For the first time, Sn3O4 is identified as the most effective electrocatalyst for CO2RR among SnOx-based materials towards carbonaceous products by density functional theory calculation and experimental work. An optimized adsorption strength of intermediates is achieved on Sn3O4 owing to the originally synergistic Sn2+ and Sn4+ effect resulted from the unique electronic structure of Sn3O4. Additionally, with an up-shifted band structure, Sn3O4 imparts the moderate adsorption energies of *H and HCOO* intermediate, which suppresses the hydrogen evolution reaction and promotes the intrinsic catalytic efficiency of CO2RR. The synthesized Sn3O4 electrocatalyst delivers a carbonaceous faradic efficiency of ∼97.7% with a partial current density of 16.6 mA/cm2 at −0.9 VRHE. The corresponding overpotential of 190 mV is lower than the values from most of the reported SnOx-based electrocatalysts.