Weakening key intermediates bindings on SnO nanodisks boosting high activity and selectivity for formate production by electrochemical CO2 reduction

The renewable energy powered electrochemical CO 2 reduction (ECO 2 R) to the value-added chemicals is not only conducive to store intermittent renewable energy but also to reduce CO 2 emission, leading to a carbon neutral society. Herein, novel SnO nanodisks have been developed for highly selective formate production by ECO 2 R. The Faraday efficiencies of formate on SnO nanodisks all exceed 90% with the partial current density of formate ranging from 9.0 to 300.4   mA   cm -2 , which is one of the widest potential range for highly selective formate production. In addition, the energy efficiency of formate production reaches 61% in a gas diffusion full cell. Electrochemical tests indicate that the morphology and the electronic structure of SnO nanodisks both contribute to the weakening of the binding of *CO 2 − intermediate. The density functional theory simulations indicate that the Sn 2+ sites weaken the binding of *OCHO intermediate than Sn 0 and Sn 4+ sites. The decreased binding property of *CO 2 − and *OCHO intermediates on SnO nanodisks promotes their protonation and the desorption of formate, thus reducing the overpotential for formate production and boosting the kinetics for ECO 2 R.