title: Catalytic activity of MCM-48-, SBA-15-, MCF-, and MSU-type mesoporous silicas modified with Fe3+ species in the oxidative dehydrogenation of ethylbenzene in the presence of N2O.
abstract: MCM-48, SBA-15, MCF, and MSU mesoporous silicas were used as supports for a deposition of Fe oxide species. Iron was introduced using two different methods: the wetness impregnation and the molecular designed dispersion (MDD). The obtained catalysts were characterized with respect to their textural parameters (BET), chemical composition (electron microprobe analysis), and reducibility (TPR). The coordination environment of Fe was determined using EPR and UV-vis/DRS. The samples were tested as catalysts in the oxidative dehydrogenation of ethylbenzene to styrene in the presence of N(2)O. An influence of Fe dispersion and reducibility on the catalytic activity was discussed. Isolated Fe(3+) species appeared to be more selective in the styrene formation, whereas iron oxide clusters showed a higher selectivity in total oxidation of aromatic hydrocarbons. The reaction system was well described by the Mars- van Krevellen mechanism.
authors.affiliation: Jagiellonian University, Faculty of Chemistry, Ingardena 3, 30-060 Kraków, Poland. kustrows@chemia.uj.edu.pl
authors.forename: Piotr
authors.initials: P
authors.lastname: Kuśtrowski
authors.forename: Lucjan
authors.initials: L
authors.lastname: Chmielarz
authors.forename: Janusz
authors.initials: J
authors.lastname: Surman
authors.forename: Ewa
authors.initials: E
authors.lastname: Bidzińska
authors.forename: Roman
authors.initials: R
authors.lastname: Dziembaj
authors.forename: Pegie
authors.initials: P
authors.lastname: Cool
authors.forename: Etienne F
authors.initials: EF
authors.lastname: Vansant