Immobilization of a Rh-based Organometallic Catalyst within Metal-Organic Framework
Résumé
The confinement of organometallic catalyst inside the cavity of porous materials was reported to enhance selectivity and activity.
Metal-Organic-Framework are new porous and crystalline hybrid organic-inorganic materials which appear to be appealing platforms for immobilization of organometallic catalyst as already reported by our group.
The first photosensitization of a rhodium-based catalytic system for CO2 reduction is reported, with formate as the sole carbon-containing product. Through post-synthetic ligand exchange methodology, we successfully proceeded to the heterogenization of this molecular catalyst via the synthesis of a new metal-organic framework (MOF) Cp*Rh@UiO-67.
While the catalytic activities of the homogeneous and heterogeneous systems are found to be comparable, the MOF-based system is more stable and more selective for formate. Furthermore it can be recycled without loss of activity. For formate production, an optimal catalyst loading of ~10% molar Rh incorporation is determined. Through the study of the behaviour of MOF systems having a controlled Rh loading, competitive catalytic reaction occurring inside the Cp*Rh@UiO-67 framework are postulated.