Selective Electrochemical CO2 Reduction tuned by N Configuration on graphitic Shells of Nickel Particles

Despite of high conductivity and reducing ability, transition metal nanoparticles tend to aggregate and unavoidably impact the selectivity during the proton-coupled reduction process of CO ₂RR. New strategy to regulate and utilize the electronic property of transition-metal particles allows for effective tuning of eCO ₂RR activity. Through simple creation of N-doped carbon shells surrounding Ni nanoparticles and controlling the amount and arrangement of the N atoms, successful and long-lasting electrochemical reduction of CO ₂ was accomplished. The inherent HER activity was almost completely suppressed. It exhibited FE _CO above 90 % in a 500 mV potential window, with the optimal up to 96.5 % at −0.78 V vs RHE. In flow cell electrolysis, a current density of 289.4 mA/cm ² was achieved with Faradic efficiency of 96.4 % towards CO. The results of control experiments using different catalysts imply that electron transfer between Ni core and shells was significantly influenced by the property of N atoms. High content of graphitic nitrogen is crucial for the catalytic performance.