| Reduction of carbon dioxide to useful chemicals and fuels is of significant interest. Transition metal complexes, such as tricarbonyl rhenium(I) compounds, are efficient molecular catalysts for photocatalytic carbon dioxide reduction. To improve the stability and catalytic activity of homogeneous catalysts, a mesoporous silica material, SBA-15, was synthesized and applied as catalyst support for immobilizing the tricarbonyl rhenium(I) compound via both covalent bonding and physical adsorption. The covalently bonded tricarbonyl rhenium(I) catalyst in SBA-15 exhibited excellent stability and good activity during the photocatalytic reduction process, compared with its homogeneous counterpart and the physically absorbed one. Another solid-state nano-material, Kaolin, was also employed as a catalyst support for the covalent attachment of tricarbonyl rhenium(I) compound. The surface functionalized Kaolin displayed some new features in infrared studies due to the unique layered structure of Kaolin materials. These new features were further investigated with FTIR spectroscopy in the presence of a sacrificial electron donor. The synthesis and characterization of different microporous and mesoporous materials are also discussed. |
