Heterogeneous tungsten-based catalysts for the epoxidation of bulky olefins

This paper discusses the design of different W and PW heterogeneous catalys ts. The first part focuses on the electrostatic immobilization of those spe cies on organic resins. Ln the second part, some new silica materials are s ynthesized as carrier materials for PW species. Both electrostatic immobili zation and covalent linking of the species on the modified silica materials are discussed. Besides a thorough spectroscopic study (FT-IR, Raman, NMR, TGA and EPMA), the catalytic properties of the designed catalysts are evalu ated for the epoxidation of a variety of bulky olefins. (C) 2000 Elsevier S cience B.V. All rights reserved.