Boosting hydrocarbon conversion via Cu-doping induced oxygen vacancies on CeO2 in CO2 electroreduction

Conversion of CO2 back to hydrocarbons is the most direct way of closing the "carbon cycle", and its significance is further enlarged if this process is driven by renewable energies such as electricity. However, precisely controlling the product selectivity towards hydrocarbons against the competitive hydrogen evolution remains challenging, especially for Cu-based catalysts. Herein, we report a novel defect engineering strategy, by which Cu-doping-induced oxygen vacancies on CeO2 nanorods were effectively created, with adjustable vacancy/Cu ratio. The resulting optimum catalyst shows up to 79% catalytic current density to hydrocarbons (excluding CO), with 49% faradaic efficiency to CH4. Experiments and density functional theory unveil that the ratio between oxygen vacancy and Cu affects significantly the formation of *CHO and activation of H2O, which leads to the following deep hydrogenation to hydrocarbons. These findings may spur new insights for designing and developing more controllable chemical process relevant to CO2 utilization. (c) 2024 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by ELSEVIER B.V. and Science Press. All rights are reserved, including those for text and data mining, AI training, and similar technologies.