Electrochemical reduction of CO2 via a CuO/SnO2 heterojunction catalyst

Copper-based materials, widely accepted as favorable catalysts for electrocatalytic reduction of carbon dioxide, are usually encountered with side-reaction problems in the experimental practice, leading to low catalytic selectivity for specific products and inducing competitive hydrogen evolution reaction. In this work, we report a novel CuO/SnO2 heterojunction structured catalyst with abundant CuO/SnO2 interfaces to diminish the side-reaction during the CO2 reduction reaction (CO2RR). Our catalyst exhibits exceptionally high selectivity for C1 products in electrochemical CO2RR with Faradaic efficiencies (FE) over 80% in a broad potential window ranging from −0.78 V to −1.06 V vs. RHE. Specifically, our catalyst reaches the highest FE of 86% at −0.87 V vs. RHE and remains stable for over 9000 s. The impressive performance of our heterojunction catalyst is attributed to the acceleration of the electron transportation at the CuO/SnO2 interfaces, which boosts the generation of active intermediates and facilitates the formation of C1 products in the CO2RR process. Such a new methodology of catalyst synthesis can be considered an effective strategy for regulating the selectivity of CO2RR products for copper-based materials.