Host-Guest Interactions in a Metal-Organic Framework Isoreticular Series for Molecular Photocatalytic CO2 Reduction

A strategy to improve homogeneous molecular catalyst stability, efficiency, and selectivity is the immobilization on supporting surfaces or within host matrices. Herein, we examine the co-immobilization of a CO2 reduction catalyst [ReBr(CO)(3)(4,4 '-dcbpy)] and a photosensitizer [Ru(bpy)(2)(5,5 '-dcbpy)]Cl-2 using the isoreticular series of metal-organic frameworks (MOFs) UiO-66, -67, and -68. Specific host pore size choice enables distinct catalyst and photosensitizer spatial location-either at the outer MOF particle surface or inside the MOF cavities-affecting catalyst stability, electronic communication between reaction center and photosensitizer, and consequently the apparent catalytic rates. These results allow for a rational understanding of an optimized supramolecular layout of catalyst, photosensitizer, and host matrix.

Automated summary

The co-immobilization of a CO2 reduction catalyst and a photosensitizer within metal-organic frameworks was studied, with specific host pore size affecting the spatial location of the catalyst and photosensitizer. This spatial arrangement influenced catalyst stability, electronic communication, and catalytic rates, providing insights for an optimized supramolecular layout.