Concerted Cation–Electron Transfer Mechanism for CO2 Electroreduction

05 November 2021, Version 1
This content is a preprint and has not undergone peer review at the time of posting.


Converting carbon dioxide (CO2) into valuable products is one of the most important processes for a sustainable society. Especially, the electrochemical CO2 reduction reaction (CO2RR) offers an effective means, but its reaction mechanism is not yet fully understood. Here, we demonstrate that concerted cation–electron transfer (CCET) is a key catalytic step in the CO2RR to carbon monoxide. The first-principles-based multiscale simulation identifies a single cation that coordinates a CO2− intermediate adsorbed on Ag electrode. The CCET is experimentally verified by a collapse of the CO2RR polarization curves upon correcting for the thermodynamic activity of the cation. As further confirmation, a kinetic study shows that the CO2RR obeys first-order kinetics on the local cation concentration at the electric double layer (estimated by measuring the electrode surface charge). Finally, this work unveils the fundamental origin of different CO2RR activity depending on the species of alkali metal cation, and further highlights the importance of ion-pairing tendency of the cations for electrochemical interface design to achieve high-performance CO2 electrolysis.


CO2 reduction
Electron transfer
Reaction mechanism
Multiscale modeling
Electrified interface

Supplementary materials

Supporting information
Supplementary notes and figures


Comments are not moderated before they are posted, but they can be removed by the site moderators if they are found to be in contravention of our Commenting Policy [opens in a new tab] - please read this policy before you post. Comments should be used for scholarly discussion of the content in question. You can find more information about how to use the commenting feature here [opens in a new tab] .
This site is protected by reCAPTCHA and the Google Privacy Policy [opens in a new tab] and Terms of Service [opens in a new tab] apply.