Photo-Driven CO2 Reduction With a Heterogenized Re Catalyst in the Metal–Organic Framework PCN-777: Effects of Catalyst Loading and Anchoring Strategy on Catalysis

This study explores the impact of (i) different installation modes of the molecular rhenium catalyst Re within the PCN-777 metal–organic framework (MOF) and (ii) catalyst loading on the resulting catalytic performance and recyclability of the different hybrid materials in the photocatalytic reduction of CO₂ to CO. Through systematic investigation, we demonstrate that a robust coordination linkage between a zirconium node of the framework and the catalyst, obtained via solvent-assisted ligand incorporation (SALI), minimizes rhenium leaching. In contrast, physical entrapment and electrostatic anchoring methods result in significant rhenium leaching after installation. Additionally, we reveal how the installation mode influences the electronic properties of the catalyst, which allows us to tune the catalytic activity. Furthermore, based on these results, we determine the optimal loading and concentration of Re within the MOF matrix for photocatalytic CO₂ reduction.

This study explores the impact of different installation modes of the molecular rhenium catalyst Re within the PCN-777 metal–organic framework, comparing physisorption, electrostatic bindind and solvent-assisted ligand incorporation (SALI), with the latter being the preferred installation mode in light of both catalytic performance and recyclability of the resulting hybrid materials for the photocatalytic reduction of CO₂ to CO. Furthermore, the optimal Re loading and concentration within the MOF matrix is established using the SALI method.