Highly selective photocatalytic reduction of CO2 to ethane over Au-O-Ce sites at micro-interface

To date, the efficient photocatalytic conversion of CO2 into high-value C2 products remains a great challenge. Herein, the Au-CeO2 nanocomposite with Au-O-Ce sites at the micro-interface was developed to achieve a highly selective conversion of CO2 into C2H6. This can be partially ascribed to the formation of key intermediates of COCO* was confirmed via in-situ Fourier transform infrared (FTIR) spectroscopy, indicating that the Au-CeO2 micro-interface could prompt the multi-electron reduction of CO* before desorption, and enable the production of C2 species. Moreover, theoretical calculations suggested that Au-O-Ce sites at the micro-interface could reduce the energy barriers for the formation of COOH* and COCO*, facilitating the production of C2H6. Therefore, the Au-CeO2 nanocomposite exhibited a C2H6 production rate of 11.07 µmol g−1 h−1 and high electron selectivity of 93.1 % (product selectivity: 65.3 %), which is comparable with most state-of-the-art photocatalysts.