Molecular understanding of cation effects on double layer and its significance to CO-CO dimerization

Abstract Cation effects have been shown in numerous experiments to play significant role electrocatalysis. To understand these at molecular level, we systematically investigate the structures and capacitances of electric double layers (EDLs) with a variety cations as counter charges Pt(111)-COad/water interfaces ab initio dynamics (AIMD). It is encouraging find that computed Helmholtz for different are quantitative agreement experiment, trend cation on shows clear correlation interfaces, which closely related their sizes hydration energies. More importantly, demonstrate key descriptor measuring activity CO-CO dimerization, rate-determining step C2 + formation electroreduction CO CO2. Our work provides atomistic insights into electrocatalysis crucial optimizing electrode electrolyte materials.