The other possibility is that the reduction of CO 2 (at least the first reduction step) happens beyond the condensed layer of counter-ions at the EDL and not directly at catalyst surface. We believe that it is highly unlikely that all the CO 2 reduction steps occur at the EDL as it would not be able to explain the major deviation between the CO 2 reduction products amongst different metallic catalysts . However, the involvement of the solvated cations in the reduction of CO 2 could be one of the reasons for the difference in performance of systems using different cation types. Ab-initio quantum-mechanical methods need be developed to study the first CO 2 reduction step in the presence of the condensed EDL to compare the energetics of the potential pathways.