Energy cost is a long-neglected but crucial issue for electrocatalytic carbon dioxide reduction reactions (CO2RRs). So far, achieving efficient CO2RR at a low energy cost is a major unresolved challenge. Herein, energy-efficient CO2-to-CH3OH conversion by synergistically increasing the amount of favorable intermediates and depressing H2 generation is reported. The designed precursor electrocatalyst undergoes in situ reduction, forming Cu−C60 and ZnO−Cu dual interfaces. Cu−C60 induces an *H-rich surface, decreasing the hydrogenation barrier and lowering the required voltage. *H-modified ZnO-Cu alters the mechanism of electron transfer and improves the conversion selectivity. As a result, at an applied potential as low as −0.63 V versus a reversible hydrogen electrode, a cathodic energy efficiency of 50.5% and a faradaic efficiency of 78.3% for CH3OH is obtained. This work unlocks an unconventional route for improving the catalytic performance and energy efficiency of electrocatalysts, addressing the concern of energy costs for electrocatalyzed CO2RR.
