Hydrophobic carbon quantum dots with Lewis-Basic nitrogen sites for electrocatalyst CO2 reduction to CH4

Metal-free carbon-based catalysts offered a promising alternative for efficient electrochemical carbon dioxide reduction (ECO2RR), presenting potential advantages over transition metal-based counterparts. However, challenges such as low Faraday efficiencies and limited current densities persist. Herein, we synthesized CQDs with high Lewis basic sites to enhance CO2 adsorption and activation, resulting in an optimized CQD-2 catalyst that achieved a Faradaic efficiency of 52.00 % and a current density of 178 mA cm-2 for CH4 production. In situ characterizations unveiled that CO2 was activated into *COOH intermediates, which further converted to *CO species. Concurrently, activated H2O molecule ionized into protons, facilitating reaction kinetics. This research provides valuable insights into designing carbon-based catalysts with high Lewis base content, offering significant prospects for advancing high-performance ECO2RR technologies.