While from a strictly energetical perspective, there is little difference between the chloride and the metal surface for CO adsorption, for CO 2 we notice a significant increase in the adsorption energy on the NaCl(111) surface. Its stronger adsorption on NaCl(111) is further reflected in its modified adsorption structure (see Fig. ), in which the CO 2 molecule is no focus on one specific system consisting of PC, either with or without sodium perchlorate salt as the electrolyte mixture in contact with a sodium metal surface. We first report the experimental findings using GC measurements.