Highly selective CO2-to-CO electroreduction on multisite coordinated single-atom-modified atomic cluster Cu-based catalyst

ABSTRACT Metal single-atom/atomic cluster catalysts (SA/AC) have emerged as effective electrocatalysts for the CO 2 reduction reaction (CO 2 RR) due to their high metal atom utilization and controllable metal coordination environments. However, the designing and tuning of the local electronic environments of SA/AC ensembles remain a significant challenge. In this work, we develop a single-atom-modified atomic cluster copper catalyst (Cu SA/ACs) for CO 2 RR. The SA/AC-induced modulation of the local electronic structure enhances CO 2 adsorption on the atomic cluster; additionally, the atomic cluster provides abundant active hydrogen for CO 2 protonation by mediating hydrolysis dissociation on the SAs. Consequently, compared to copper single-atom catalysts (Cu SACs), the Cu SA/ACs exhibit significantly improved activity, the current is 3.6 times that of Cu SACs, and the Faradaic efficiency of CO rose from 27.15% to 98.94%. The Cu SA/ACs catalyst can efficiently reduce CO 2 to CO in flow-cell configuration, and the CO selectivity is 93.06% at a current density of 600 mA cm –2 . The maximum energy efficiency of the cathode is 61.9%, which is superior to that of most CO 2 -to-CO catalysts. This work provides a new perspective for developing efficient SA/AC catalysts.