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 CO2 reduction reaction (CO2RR) 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 CO2RR. The SA/AC-induced modulation of the local electronic structure enhances CO2 adsorption on the atomic cluster; additionally, the atomic cluster provides abundant active hydrogen for CO2 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 CO2 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 CO2-to-CO catalysts. This work provides a new perspective for developing efficient SA/AC catalysts.