High-activity, single-site mesoporous WO3-MCF materials for the catalytic epoxidation of cycloocta-1,5-diene with aqueous hydrogen peroxide

• Published in: Journal of catalysis Vol. 256; no. 2; pp. 259 - 267
• Main Authors: RUIHUA GAO, XINLI YANG, DAI, Wei-Lin, YINGYI LE, HEXING LI, KANGNIAN FAN
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier 10.06.2008; Elsevier BV
• Subjects: Catalysis; Catalysts; Chemical engineering; Chemistry; Colloidal state and disperse state; Emulsions. Microemulsions. Foams; Exact sciences and technology; General and physical chemistry; Materials science; Oxidation; Porous materials; Silica; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry; Mesocellular silica foam (MCF) catalyst; Binary compound; Catalytic reaction; Hydrogen peroxide; Transition element compounds; Cycloocta-1,5-diene; Dienic compound; Porous material; Silica; Isolated tetrahedral {WO4} species; Mesoporosity; Heterogeneous catalysis; Tungsten oxide; Foam; Epoxidation; Catalyst
• ISSN: 0021-9517; 1090-2694
• DOI: 10.1016/j.jcat.2008.03.017

For the first time, the high-activity, single-site mesoporous WO3-MCF materials were synthesized and characterized by N2 sorption, TEM, UV-vis DRS, UV-Raman, and XPS. It was found that the dispersion and nature of the tungsten species depend strongly on the tungsten oxide content and the support characteristic. The novel catalyst remains a highly ordered mesostructure of the silica support. The catalytic performance of the materials in the epoxidation of cycloocta-1,5-diene with aqueous H2O2 was investigated. The excellent catalytic performance of WO3-MCF in the selective oxidation of cycloocta-1,5-diene was attributed to the presence of isolated tetrahedral {WO4} species and the unique pore structure. The novel catalyst can be easily recycled after reaction and reused many times with no significant loss of activity. The good stability can be attributed to the presence of isolated tungsten species anchored on the support through W[single bond]O[single bond]Si covalent bonds. [PUBLICATION ABSTRACT]