Ultra-Fast Pulsed Discharge Preparation of Coordinatively Unsaturated Asymmetric Copper Single-Atom Catalysts for CO₂ Reduction

Single-atom catalysts possess great potential for applications in electrochemical carbon dioxide reduction reactions. Recently, the fast and low-cost preparation of highly efficient single-atom catalysts remains a challenge. Herein, a high-density current generated by pulsed discharge is employed for the formation of graphene aerogel anchored Cu single atom catalysts perfectly. The Cu atoms decomposed by Cu(NO₃)₂•xH₂O are fixed on graphene under the local transient high temperature and intense electromagnetic field. The activity and selectivity of formic acid are correlated with the coordinatively unsaturated Cu─N₁O₁ moieties, reaching an optimal Faradaic efficiency (93.7%) at −0.9 V versus a reversible hydrogen electrode (RHE). In situ characterizations reveal that the asymmetric Cu─N/O structure in a pinched state displays better catalytic activity in CO₂RR. Density functional theory results indicate that the Cu─N₁O₁ sites regulate the adsorption configuration of intermediates and lower the energy barrier for the hydrogenation of ^*OCHO species, thereby promoting CO₂-to-HCOOH conversion.