Tailoring the Electrochemical Protonation Behavior of CO2 by Tuning Surface Noncovalent Interactions

Simultaneously boosting the activity and selectivity of CO2 reduction catalysts remains a challenge. In this work, surface-adsorbed hydroxyl (OHad) on the SnO promoted CO2 reduction into formate through noncovalent interactions (NCIs). The SnO nanosheet with bound hydroxyl groups achieves a high Faradic efficiency of 90.5% and a partial current density of 61.8 mA cm(-2) for formate production at -1.06 V vs reversible hydrogen electrode, which is substantially better than the performance of the pristine material. Theoretical analysis reveals OHad-introduced NCIs can promote CO2 adsorption, activation, and conversion into formate. Moreover, the O-ad enhances hydrogen species adsorption to maintain the continuity of OHad-introduced NCIs. Importantly, OHad-introduced NCIs are demonstrated as a general strategy that can be applied to boost CO2 hydrogenation of a series of metal oxides including SnO, CuO, Bi2O3, and TiO2. This study provides molecular-level insights into the rational catalyst design for CO2 reduction and beyond.

Automated summary

This study demonstrates that enhancing CO2 reduction catalysts through noncovalent interactions can improve the selectivity and activity of SnO catalysts, leading to efficient formate production. Moreover, the introduction of hydroxyl groups can be a general strategy for CO2 hydrogenation on various metal oxides.