Pyrene as a Redox Partner for CO2 Electroreduction Catalyzed by a Zinc Cyclam-Pyrene Complex

Molecular coordination and organometallic complexes represent a well-established class of catalysts for the electroreduction of CO2 into value-added products such as CO and formic acid. However, advancing these systems into solid-state, electrode-supported materials remains a key challenge. Here, we report a Zn(II)-cyclam complex functionalized with a pyrene moiety and immobilized on carbon nanotubes, forming a robust cathode material that achieves high CO2-to-CO selectivity (Faradaic efficiency >95%) and catalytic performance (turnover number of 19500 after 3.5 h). Zn-based molecular catalysts are exceedingly rare due to the redox-inactive nature of Zn(II). Our density functional theory (DFT) calculations suggest that catalysis proceeds through a synergistic mechanism, in which the redox-active pyrene facilitates electron transfer, while the Zn(II) center serves as a Lewis acid site for CO2 binding and activation.