A customized Sn3O4 interface to stabilize *CO2 intermediate for efficient electrocatalytic CO2 reduction

Interfacial regulation strategy is considered as an effective approach to enhance the electrocatalytic performance. Herein, we demonstrate an appropriate carbon nanotubes-modified Sn3O4 electrocatalysts with maximum carbonaceous Faradaic efficiency of 91 % at −0.79 V vs. RHE, and over 86 % at −0.69 to −1.09 V vs. RHE. The carbonaceous Faradaic efficiency of 20 %CNT/Sn3O4 catalyst remains above 90 % at −0.79 V over 10 h. The chemical interfacial interaction of carbon nanotubes-modified Sn3O4 catalysts facilitates the adsorption and activation of CO2. The in situ Raman results confirm the formation of key formate intermediates and the stabilization of catalyst structure. More importantly, CO2 reduction coupling ethylene glycol (EG) oxidation reduces energy consumption and coproduces value-added formate in a two-electrode system. This work provides a reference for constructing interface-modulated metal oxide electrocatalysts and coproducing formate for co-electrolysis systems.