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RESEARCH PRODUCT

Epoxidation of dibenzocycloalkenes on Ti–Ge-MCM-41 and Ti-SBA-15 catalysts

D. Trong OnPedro AmorósMircea D. BanciuL. PârvulescuA. PopescuI. MandacheSerge KaliaguineD. BeltranVasile I. Parvulescu

subject

Inorganic chemistryEpoxideGeneral ChemistryCondensed Matter PhysicsHeterogeneous catalysisCatalysisTetraethyl orthosilicatechemistry.chemical_compoundchemistryMCM-41Mechanics of MaterialsCycloocteneCyclohepteneGeneral Materials ScienceMesoporous materialNuclear chemistry

description

Abstract Epoxidation of a series of dibenzocycloalkenes: phenanthrene, 5H-dibenzo[ a , e ]cycloheptene, 5H-dibenzo[ a , c ] cycloheptene, 5,6-dihydrodibenzo[ a , e ]cyclo-octene, and dibenzo[ a , e ]cyclooctene with hydrogen peroxide was investigated on Ti- and Ge-modified Ti-incorporated-type mesoporous catalysts including MCM-41 and SBA-15 structures looking for the effect of the porous texture and Ge-promoting on both activity and selectivity to epoxide and H 2 O 2 efficiency. Ti–Ge-MCM-41 catalysts (Si/Ti = 43; Si/Ge = 85 and Si/Ti = 41; Si/Ge = 62) were prepared by a one-pot surfactant-assisted procedure based on the use of a cationic surfactant (CTAB, cetyltrimethylammonium bromide), as structure directing agent, and a complexing polyalcohol (2,2′,2″-nitriletriethanol), able to harmonize the hydrolysis and co-condensation reaction rates of the different heteroelements and the self-assembling processes between the inorganic precursors and the surfactant micelles. Ti-SBA-15 catalysts were prepared in a strong acidic medium (2 M HCl solution) using Pluronic P-123 (HO(CH 2 CH 2 O) 20 (CH 2 CH(CH 3 )O) 70 (CH 2 CH 2 O) 20 H),as surfactant and tetraethyl orthosilicate and tetrapropyl orthotitanate as silicon and titanium sources. All these materials were characterized by N 2 adsorption–desorption isotherm measurements, XRD, TEM and DR–UV–Vis, both as fresh and used catalysts.

https://doi.org/10.1016/j.micromeso.2005.01.024