Surface Energy Tuning on Cu/NC Catalysts for CO Electroreduction

Electrochemical CO reduction reaction (CORR) represents a potential approach to generate value-added products. Nonetheless, it is generally challenging for conventional measurements to quantify the catalytic surface properties, due to the geometric blockage and synergistic effect from the support. Herein, the surface energy of copper-loaded nitrogen-doped carbon (Cu/NC) was investigated by adsorption with specific functional groups using inverse gas chromatography (IGC). The dispersive component (gamma SD) and the acid/base character of the surface energy were determined using non-polar and polar probe molecules. The specific free energy (Delta GAB), the enthalpy of adsorption (Delta HAB), and the acidic (KA) and basic (KD) parameters were obtained, which allowed to provide the affinity information of intermediates such as *CHO, *OCH2COH, and *H. The surface energy analysis suggested that the Cu/N0.17C catalyst with the highest basic parameter (KD = 7.350) and optimal acid interaction (KA/KD similar to 0.046) exhibited high catalytic performance in the acetate production, with a Faradaic efficiency (FE) of 63% and a partial current density of -330 mA center dot cm-2. The exposed catalytic sites on Cu/NC were suggested to activate H2O and stabilize oxygenate intermediates favorably for the electrochemical CO-to-acetate conversion.