title: Toluene oxidation on titanium- and iron-modified MCM-41 materials.
abstract: Iron- and titanium-modified MCM-41 materials, prepared by direct synthesis at ambient temperature or wet impregnation technique, were investigated using X-ray diffraction (XRD), transmission electron microscopy (TEM), temperature-programmed reduction (TPR), UV-vis diffuse reflectance, Mössbauer and FT-IR spectroscopies. Their catalytic behavior was studied in total oxidation of toluene. Materials with high surface area and well-ordered pore structure were obtained. The increase of the titanium content (up to 50%) in the bisubstituted, iron and titanium containing materials leads to partial structure collapse of the silica matrix. Finely dispersed anatase particles were also formed during the impregnation procedure. The catalytic activity of the bisubstituted materials was influenced by the method of their preparation, but higher catalytic stability could be achieved, compared to iron monosubstituted one. The nature of the catalytic active sites is discussed.
authors.affiliation: Institute of Organic Chemistry with Centre of Phytochemistry, Bulgarian Academy of Sciences, Sofia, Bulgaria. mpopova@orgchm.bas.bg
authors.forename: M
authors.initials: M
authors.lastname: Popova
authors.forename: A
authors.initials: A
authors.lastname: Szegedi
authors.forename: Z
authors.initials: Z
authors.lastname: Cherkezova-Zheleva
authors.forename: I
authors.initials: I
authors.lastname: Mitov
authors.forename: N
authors.initials: N
authors.lastname: Kostova
authors.forename: T
authors.initials: T
authors.lastname: Tsoncheva
mesh_terms: D002384:Catalysis; D020134:Catalytic Domain; D007501:Iron; D008422:Materials Testing; D010084:Oxidation-Reduction; D016062:Porosity; D012822:Silicon Dioxide / Q000138:chemical synthesis / Q000737:chemistry*; D014025:Titanium; D014050:Toluene / Q000737:chemistry*; D014865:Waste Disposal, Fluid / Q000379:methods*
chemical_list: C509968:MCM-41; C009495:titanium dioxide; D014050:Toluene; D012822:Silicon Dioxide; D014025:Titanium; D007501:Iron