Nitrogen Dopant Induced Highly Selective and Durable CO Electroreduction into Formate on the InO Surface.

The inactive and unstable active sites limit the development of the electrochemical CO reduction reaction (CORR) under a large current density. Herein, nitrogen-doped InO was designed, which achieved a formate Faradaic efficiency (FE) of 97.6% with a formate partial current density () of 390.6 mA cm. Moreover, it maintained an FE above 90% for over 20 h at 200 mA cm in a flow cell, while pristine InO lost CORR activity within 4 h. It was found that nitrogen doping induced the electrons to transfer from the catalyst to the reactant molecules more easily and quickly to avoid the corrosion of the catalyst caused by electron accumulation. Meanwhile, the nitrogen dopant favored the adsorption of CO intermediates in the form of the OCO* adsorption mode and promoted the formation of formate-related *CO and *OCHO intermediates at lower potentials, thus facilitating formate production. This fundamental insight aids in the development of highly active catalysts with ultrastability under a large current density.