Self-Assembled Liposomes Enhance Electron Transfer for Efficient Photocatalytic CO<sub>2</sub> Reduction
Santiago Rodríguez‐Jiménez, Hongwei Song, Erwin Lam, Demelza Wright, Andrea Pannwitz, Shannon A. Bonke, Jeremy J. Baumberg, Sylvestre Bonnet, Leif Hammarström, Erwin Reisner
Abstract
reduction in liposomes using precious metal-free catalysts. Using sodium ascorbate as a sacrificial electron source, a membrane-anchored alkylated cobalt porphyrin demonstrates higher catalytic CO production (1456 vs 312 turnovers) and selectivity (77 vs 11%) compared to its water-soluble nonalkylated counterpart. Time-resolved and steady-state spectroscopy revealed that self-assembly facilitates this performance enhancement by enabling a charge-separation state lifetime increase of up to two orders of magnitude in the dye while allowing for a ninefold faster electron transfer to the catalyst. Spectroelectrochemistry and density functional theory calculations of the alkylated Co porphyrin catalyst support a four-electron-charging mechanism that activates the catalyst prior to catalysis, together with key catalytic intermediates. Our molecular liposome system therefore benefits from membrane immobilization and provides a versatile and efficient platform for photocatalysis.