“…molecule from the RWGS reaction is linked through a carbon (i.e., "linear CO") to NiO (i.e., Ni 2+ ions), rather than through two adjacent surface atoms (i.e., "bridged CO"). 40 Therefore, CO in "linear form" is reversibly chemisorbed, resulting in a weaker bond with the surface, 40 and thus an easier desorption to the gas-phase (i.e., higher activity toward the RWGS reaction). Although the observed increase of the CO production rate (under anodic polarization) could be also ascribed to the electro-oxidation of CO 2 on the Au electrode, blank experiments with Au/YSZ/Au sample showed that the catalytic contribution of the Au electrodes is relatively small while the rate increase under positive or negative polarization is negligible (Fig.…”