In situ formation of Cu-Sn bimetallic catalysts for CO₂ electroreduction to formate with high efficiency

In this work, we proposed a method to prepare Cu-Sn bimetallic catalysts, which are composed of Cu⁰, Sn⁰, and SnO₂ by combination of a hydrothermal process and in situ electrochemical reduction. The catalysts exhibited efficient electrocatalytic activity towards the conversion of CO₂ to formate with a faradaic efficiency of 92.9% and a current density of 632 mA cm⁻². The partial current density was very high comparing with other Sn-based catalysts reported. The presence of Cu promoted the existence of electron-deficient centers and realized the regulation of Cu on Sn, which promoted the protonation reaction of CO₂˙⁻, leading to improved activity and selectivity to formate.