Photocatalytic properties of the SBA-15 mesoporous silica molecular sieve modified with titanium

Influence of the acid/base and redox properties of catalysts in the gas-phase dehydration–dehydrogenation of cyclohexanol on iron and titania containing mesoporous materials

“…2) of the studied materials exhibit a broad absorption peak in the 210-250 nm region attributable to isolated, tetrahedrally coordinated metal species [17][18][19]. According to [17,18], the shift of the band to higher wavelength ([350 nm) of the iron modified materials, most probably arise from the presence of oligomeric FeO x species.…”

Synthesis and NMR Characterization of Titanium and Zirconium Oxides Incorporated in SBA-15

“…The Q 3 /Q 4 ratio increases both for Ti-SBA-15 and Zr-SBA-15 catalysts as compared to SBA-15. This can be due to the ion modification of SBA-15 [18] or the enrichment of the surface by silica since it is thermodynamically more favourable [6]. In other words, Zr or Ti incorporated silicas can result in Q 3 -like environments [29] where hydrogens in OH groups or silicons in Q 4 units are replaced by Ti or Zr, i.e.…”

“…In this study, the effect of the introduction of Ti and Zr into SBA-15 is investigated by means of 29 Si and 1 H MAS NMR spectroscopy in order to identify the bonding characteristics of the silica framework with Ti and Zr [17,18]. Furthermore, oxidation states and bonding characteristics of titania with silica framework were characterized by XPS, and the surface area and pore volume characteristics were determined via N 2 adsorption techniques.…”

Dehydrogenation of Cyclohexanol on Fe, Ti-MCM-41 Mesoporous Materials

“…3) of the modified materials exhibit a broad absorption peak in the 220-250 nm region attributable to isolated, tetrahedrally coordinated metal species [6,7,38,39]. The band at about 350 nm, characteristic for all iron containing samples most probably arise from the presence of oligomeric FeO x species in the silica matrix.…”

“…MCM-41 silica materials, with their uniform mesoporous channel structure and high specific surface area are of particular interest as catalyst support [1][2][3][4][5][6][7][8]. A wide variety of metal ions (Fe, Ti, V, Cr, Cu, etc.)…”