Study on reaction mechanism of CO2 electro-reduction to CO in organic medium: Revealed by experimental and spectroscopic Investigations

CO2 2 electrocatalytic reduction (CO2RR) 2 RR) to CO in organic electrolytes has received considerable attention due to its potential industrial application prospect. However, the reaction mechanism is not fully understood. In this study, we employed experimental observation, in-situ ATR-IRAS and Raman spectroscopy to elucidate the reaction mechanism of CO2 2 electro-reduction to CO in an organic medium. The reaction intermediates *CO2 center dot-, 2 center dot- , * (CO 2 ) 2 center dot- and *CO has been identified during CO2RR. 2 RR. Based on these results, the reaction mechanism has been discussed extensively. Density Functional Theory (DFT) analysis further indicates that the electrolytic CO2 2 reduction to CO in organic electrolyte is relatively more difficult than that in aqueous solutions.