Benzene Hydrogenation by Silica-Supported Catalysts Made of Palladium Nanoparticles and Electrostatically Immobilized Rhodium Single Sites
The complex [Rh(cod)(dppp)]OTf (Rh(cod)) has been immobilized onto silica-supported palladium nanoparticles (Pd/SiO2) via a dual H-bond/ionic interaction (dppp = 1,3-bis(diphenylphosphino)propane; cod = cycloocta-1,5-diene). The product obtained, Rh(cod)-Pd/SiO2, has been employed to catalyze the hy...
Saved in:
Published in | Organometallics Vol. 27; no. 12; pp. 2809 - 2824 |
---|---|
Main Authors | , , , , , , , , |
Format | Journal Article |
Language | English |
Published |
WASHINGTON
American Chemical Society
23.06.2008
Amer Chemical Soc |
Subjects | |
Online Access | Get full text |
Cover
Loading…
Summary: | The complex [Rh(cod)(dppp)]OTf (Rh(cod)) has been immobilized onto silica-supported palladium nanoparticles (Pd/SiO2) via a dual H-bond/ionic interaction (dppp = 1,3-bis(diphenylphosphino)propane; cod = cycloocta-1,5-diene). The product obtained, Rh(cod)-Pd/SiO2, has been employed to catalyze the hydrogenation of benzene to cyclohexane, showing much higher activity as compared to Pd/SiO2, while Rh(cod) grafted on bare silica (Rh(cod)/SiO2) is totally inactive. The catalyst generated by Rh(cod)-Pd/SiO2 exhibits a remarkable stability and can be recycled several times with no loss of activity, even if exposed to air. In situ and ex situ EXAFS and DRIFTS measurements, batch catalytic reactions under different conditions, deuterium labeling experiments, and model organometallic studies, taken altogether, have provided valuable mechanistic information. The reduction of benzene to cyclohexa-1,3-diene occurs with the cooperation of the two metals, while the rhodium single sites are more effective than the palladium nanoparticles in the hydrogenation of cyclohexa-1,3-diene to cyclohexane. |
---|---|
Bibliography: | istex:3069777732A346524D2FBB34F3E1A89F9BBA142B ark:/67375/TPS-V9DSLSJ7-K |
ISSN: | 0276-7333 1520-6041 |
DOI: | 10.1021/om800223d |