Synergistic Mediation: Flexible Alkanolamine-Ir Sites for Photocatalytic CO2 Reduction Coupled with Water Oxidation
Construction of metal-mediated redox sites is an appealing approach to enhance photocatalytic CO2 reduction coupled with H2O oxidation. However, conventional static redox sites generally lack spatiotemporal matching during reaction processes due to the constraints of rigid structure and the linear scaling relationship of adsorbed species. Herein, an alkanolamine-Ir synergistic system was developed, where flexible monoethanolamine (MEA) molecules function as molecular ferries to selectively adsorb CO2 via carbamate formation, while adjacent Ir nanoparticles (NPs) serve as H spillover hubs that relay protons, creating spatiotemporal adaptability that synchronizes CO2 reduction and water oxidation. In addition, time-resolved in situ spectroscopy directly captures the rapid transformation of carbamate intermediates concurrent with sustained IrOOH intermediates formation. Microkinetic modeling further demonstrates that the MEA-Ir modified system (M-Ir/ACN) creates interconnected H spillover networks between Ir NPs and MEA, facilitating efficient proton transport that drives *COOH formation with a favorable thermodynamic energy. As a result, the M-Ir/ACN achieves a 20-fold increase in CO production compared to the pristine sample while maintaining high stability throughout 45 h of continuous operation. This study presents that flexible molecular ferries boost CO2 adsorption, and deciphers how flexible molecular-metal synergy directs the trafficking of CO2-derived intermediates toward highly efficient CO2 photoreduction.