The electrochemical conversion of CO2 into multi-carbon (C2+) products offers a promising route toward sustainable energy and carbon neutrality, but is hindered by inefficient C–C coupling, especially for C3 products. Here we show a Ni single atom/Cu single cluster catalyst (Ni SAC/Cu SCC) that achieves a total Faradaic efficiency (FE) of 84.1% for C2+ products (ethanol, ethylene glycol, and acetone) in a flow cell. The FE for acetone (a C3 product) reaches 48.8%. The high acetone selectivity on Ni SAC/Cu SCC is attributed to the synergistic interplay among in-tandem catalysis, the confinement effect, and in situ-formed Cu0/Cu+ sites. Mechanistically, CO spills over from Ni sites to adjacent Cu sites and is confined within the hierarchical pore structure of the reduced graphene oxide (rGO) support, resulting in high local CO coverage on Cu sites. Concurrently, the in situ-formed Cu0/Cu+ sites enhance adsorption of the key *CO intermediate. Together, this synergy lowers the energy barriers for C–C coupling. This work provides insights into the electrosynthesis of multi-carbon products. Electrochemical CO2 conversion to multi-carbon products is hindered by inefficient C–C coupling. Here, the authors report a nickel single atom/copper single cluster catalyst that achieves high acetone selectivity through tandem catalysis, confinement, and in situ-formed Cu0/Cu+ sites.
Yang et al. (Tue,) studied this question.