Synergistic Effects of Amine Functional Groups and Enriched-Atomic-Iron Sites in Carbon Dots for Industrial-Current-Density CO 2 Electroreduction.

Metal phthalocyanine molecules with Me-N 4 centers have shown promise in electrocatalytic CO 2 reduction (eCO 2 R) for CO generation. However, iron phthalocyanine (FePc) is an exception, exhibiting negligible eCO 2 R activity due to a higher CO 2 to * COOH conversion barrier and stronger * CO binding energy. Here, amine functional groups onto atomic-Fe-rich carbon dots (Af-Fe-CDs) are introduced via a one-step solvothermal molecule fusion approach. Af-Fe-CDs feature well-defined Fe-N 4 active sites and an impressive Fe loading (up to 8.5 wt%). The synergistic effect between Fe-N 4 active centers and electron-donating amine functional groups in Af-Fe-CDs yielded outstanding CO 2 -to-CO conversion performance. At industrial-relevant current densities exceeding 400 mA cm -2 in a flow cell, Af-Fe-CDs achieved >92% selectivity, surpassing state-of-the-art CO 2 -to-CO electrocatalysts. The in situ electrochemical FTIR characterization combined with theoretical calculations elucidated that Fe-N 4 integration with amine functional groups in Af-Fe-CDs significantly reduced energy barriers for * COOH intermediate formation and * CO desorption, enhancing eCO 2 R efficiency. The proposed synergistic effect offers a promising avenue for high-efficiency catalysts with elevated atomic-metal loadings.