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 CO 2 reduction coupled with H 2 O 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 CO 2 via carbamate formation, while adjacent Ir nanoparticles (NPs) serve as H spillover hubs that relay protons, creating spatiotemporal adaptability that synchronizes CO 2 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 CO 2 adsorption, and deciphers how flexible molecular-metal synergy directs the trafficking of CO 2 -derived intermediates toward highly efficient CO 2 photoreduction.