Halogen-free acylation of toluene over FeSBA-1 molecular sieves

• Published in: Microporous and mesoporous materials 2007-03, Vol.100 (1), p.87-94
• Main Authors: Vinu, A., Krithiga, T., Gokulakrishnan, N., Srinivasu, P., Anandan, S., Ariga, K., Murugesan, V., Balasubramanian, V.V., Mori, T.
• Format: Article
• Language: English
• Subjects: Acylation; Catalysis; Catalyst; Chemistry; Colloidal state and disperse state; Exact sciences and technology; FeSBA-1; General and physical chemistry; Mesoporous; Porous materials; SBA-1; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry
• ISSN: 1387-1811; 1873-3093
• DOI: 10.1016/j.micromeso.2006.10.014

Three-dimensional cage type iron substituted mesoporous silica with different iron contents (FeSBA-1) was synthesized in a highly acidic media using cetyltriethylammonium bromide and tetraethylorthosilicate as a template and a silica source, respectively. Acylation of toluene with acetic anhydride (AA) was carried out over FeSBA-1 mesoporous catalysts with different n Si/ n Fe ratios in the temperature range 80–180 °C for a time-on-stream of 1–6 h under liquid phase conditions. The important factors affecting the conversion and the selectivity of the reaction, such as the reaction temperature, feed ratio, catalyst weight and time-on-stream were studied and the results are discussed in detail. The reaction conditions were optimized and the n AA/ n Toluene ratio of 2 and catalyst weight of 0.1 g (3.3 wt% of total reaction mixture) were maintained for all catalytic runs. It was found that the catalytic activity is strongly influenced by the amount of tetrahedral iron in the catalysts. Among the catalysts used in the present study, FeSBA-1(36) showed a high toluene conversion and selectivity to p-methylacetophenone ( p-MAP) under the optimized reaction conditions. It was also found that the selectivity for p-MAP was always higher than m-MAP and o-MAP for all the catalysts and the activity of the catalysts changes in the following order: FeSBA-1(36) > FeSBA-1(90) > FeSBA-1(120).