The catalysts' electrochemical performances for CO2 reduction were evaluated in a CO2-saturated 0.5 M KHCO3 solution using a standard three-electrode H-cell. To initially assess the eCO2RR, linear sweep voltammetry (LSV) curves were conducted for all samples. Supplementary Fig. catalytic activity. Gas products were regularly analyzed via online gas chromatography (GC), revealing that CO and H2 were the primary gases obtained across all samples. Additionally, the liquid-phase products of Au0.5/Ni-N-O-C were examined using nuclear magnetic resonance ( 1 H-NMR) spectroscopy after the electrochemical CO2 reduction processes. These analyses demonstrated the absence of any liquid products (Supplementary Fig. ). ). Additionally, various Aux/Ni-N-O-C catalysts with different Au contents are shown in Supplementary Fig. . These results demonstrate that the presence of a specific amount/density of Au nanoparticles indeed influences the generation of CO at different applied potentials. As a result, to attain the optimal activity of Au/Ni-N-O-C, it is crucial to adjust the quantity of Au reagent to a point where the formed electron tug effect could broad the potential range with high selectivity and activity toward CO. Transmittance (%) Transmittance (%) bands were observed between 2400 and 1000 cm -1 for both samples (Fig. ).