Epoxidation of alkenes with hydrogen peroxide catalyzed by ReO4–SiO2·Al2O3 and ReO4–Al2O3

Autor:	Ulrich Arnold, Michiel C. A. van Vliet, Ulf Schuchardt, Roger A. Sheldon, Dalmo Mandelli
Rok vydání:	2001
Předmět:	Process Chemistry and Technology Inorganic chemistry Cyclohexene Epoxide chemistry.chemical_element Rhenium Heterogeneous catalysis Catalysis chemistry.chemical_compound chemistry Cyclooctene Leaching (metallurgy) Physical and Theoretical Chemistry Zeolite Nuclear chemistry
Zdroj:	Journal of Molecular Catalysis A: Chemical. 168:165-171
ISSN:	1381-1169
DOI:	10.1016/s1381-1169(00)00521-5
Popis:	Rhenium oxides supported on zeolite Y, mixed silica–alumina and pure alumina were prepared by impregnation of the supports with Re 2 O 7 or NH 4 ReO 4 . The materials are active catalysts in the epoxidation of cyclooctene and cyclohexene with anhydrous H 2 O 2 in EtOAc. Catalyst stabilities with regard to metal leaching are closely correlated with the alumina content of the support and almost no leaching was observed with ReO 4 − supported on pure alumina. Stable catalysts ReO 4 –Al 2 O 3 with ReO 4 − contents up to 12 wt.% can be prepared. Higher contents result in extensive metal leaching and catalysis in the homogeneous phase. The catalyst ReO 4 (12 wt.%)–Al 2 O 3 was re-used in three catalytic runs, without loss of activity. Selectivities for cyclooctene epoxide were around 96%, whereas cyclohexanediol was obtained as the only product in cyclohexene epoxidation. Adding pyridine to the reaction mixtures, the selectivity for cyclohexene epoxide increased from 0 to 67%, however, a significant decrease in conversion was observed.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::96c4c2fd2ba4065da1d312fee6ed48d4 https://doi.org/10.1016/s1381-1169(00)00521-5 Zobrazit plný text záznamu Full Text from ScienceDirect