Aerobic Epoxidation of Olefin by Platinum Catalysts Supported on Mesoporous Silica Nanoparticles

• Published in: ACS catalysis Vol. 6; no. 7; pp. 4584 - 4593
• Main Authors: Munz, Dominik, Wang, Daoyong, Moyer, Megan M, Webster-Gardiner, Michael S, Kunal, Pranaw, Watts, David, Trewyn, Brian G, Vedernikov, Andrei N, Gunnoe, T. Brent
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 01-07-2016; American Chemical Society (ACS)
• Subjects: platinum; epoxidation; immobilized catalysts; oxygen; olefins
• ISSN: 2155-5435; 2155-5435
• DOI: 10.1021/acscatal.6b01532

We report platinum catalysts for the efficient aerobic oxidation of olefins to form epoxides and/or derived glycol monoethers. The catalystsdiaqua and dichloro PtII complexes supported by the ligand di­(2-pyridine)­methanesulfonate (dpms)are most active when they are covalently tethered to mesoporous silica nanoparticles (MSNs). Supporting the molecular Pt complexes on the MSNs prevents bimolecular catalyst deactivation. Using this strategy, >40 000 turnovers are achieved for the aerobic oxidation of norbornene in 2,2,2-trifluoroethanol. The position of the tether and the nature of other ligands in the metal coordination sphere (aqua, hydroxo, or chloro) are shown to affect the catalyst activity. The new MSN-supported Pt materials were characterized by nuclear magnetic resonance (NMR) spectroscopy, nitrogen physisorption, powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and thermogravimetric analysis (TGA).