從二氧化碳的電化學還原機制到選擇性碳碳鍵的生成：相關銅電極表面上之氧化還原理論模擬

The CO‧‧CO dimerization mechanism is investigated using Density Function Theory (DFT)　calculations on CuO(111), Cu4O3(202) and Cu2O(111) surfaces in order to characterize the potential reaction pathway on the oxide-derived Cu catalysts for CO2 reduction. With the presence of oxygen vacancy on CuO(111) and Cu4O3(202) surfaces, CO could be adsorbed at the side-on orientation on these surfaces. The side-on adsorbed orientation of CO on Cu2O(111) surface could also be identified without oxygen vacancy. The transition states of CO‧‧CO dimerization on these three surfaces are identified and the formation of OCCO as the final products are determined. The Ov-Cu4O3(202) surface, containing an oxygen vacancy, surface is found to outperform other two surfaces with the barrier predicted at 0.98 eV and thermodynamically favorable to the OCCO formation. The electronic structure of the adsorbed OCCO is analyzed by Bader charge analysis, electron localization functional and local density of state analysis. The CC triple-bond and charge-separated character for (OC)δ+(CO)δ– on Ov-Cu4O3(202) is assigned where the intrinsic mixed-valence nature of Cu interaction sits of Cu4O3 is responsible to stabilize such charge-separated OCCO species.