Oxygen-Bridged Cu Binuclear Sites for Efficient Electrocatalytic CO 2 Reduction to Ethanol at Ultralow Overpotential

Electrocatalytic CO2 reduction (CO2RR) to alcohols offers a promising strategy for converting waste CO2 into valuable fuels/chemicals but usually requires large overpotentials. Herein, we report a catalyst comprising unique oxygen-bridged Cu binuclear sites (CuOCu-N4) with a Cu···Cu distance of 3.0–3.1 Å and concomitant conventional Cu–N4 mononuclear sites on hierarchical nitrogen-doped carbon nanocages (hNCNCs). The catalyst exhibits a state-of-the-art low overpotential of 0.19 V (versus reversible hydrogen electrode) for ethanol and an outstanding ethanol Faradaic efficiency of 56.3% at an ultralow potential of −0.30 V, with high-stable Cu active-site structures during the CO2RR as confirmed by operando…

• NN
  National Natural Science Foundation of China

  Awards: 21972061, 21832003, 52071174
• NS
  Natural Science Foundation of Jiangsu Province

  Award: BK20212005
• NK
  National Key Research and Development Program of China

  Awards: 2018YFA0209103, 2021YFA1500900