title: 1H, 51V and 15N nuclear magnetic resonance studies of structure and properties of vanadia supported on TiO chi/SiO2.
abstract: 1H magic-angle spinning nuclear magnetic resonance (MAS NMR) spectra of TiO chi/SiO2 catalysts suggest the interaction of surface TiO chi species with Si-OH groups of the silica. Simultaneously, Ti-OH groups from surface titania species appear. The distribution of TiO chi species over SiO2 is non-uniform, since a considerable part of surface OH groups remains unreacted with supported titania. Supported vanadia species interact both with Si-OH and Ti-OH groups. 51V NMR spectra suggest the interaction of vanadia with supported titania species and show the non-uniform distribution of titania over the SiO2 surface. Deposition of titania as well as vanadia produces strong electron-accepting (Lewis) sites which interact with the terminal N atom of adsorbed N2O molecules, resulting in a downfield shift of the resonance in 15N NMR spectra. The acid strength of electron-accepting sites is similar in both cases. Only about 10% of the total amount of supported titania and vanadia create Lewis sites.
authors.affiliation: Boreskov Institute of Catalysis, Novosibirsk, Russia.
authors.forename: V M
authors.initials: VM
authors.lastname: Mastikhin
authors.forename: V V
authors.initials: VV
authors.lastname: Terskikh
authors.forename: O B
authors.initials: OB
authors.lastname: Lapina
authors.forename: S V
authors.initials: SV
authors.lastname: Filimonova
authors.forename: M
authors.initials: M
authors.lastname: Seidl
authors.forename: H
authors.initials: H
authors.lastname: Knözinger
mesh_terms: D000327:Adsorption; D002384:Catalysis; D004579:Electron Transport; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D009587:Nitrogen Isotopes; D011522:Protons; D012822:Silicon Dioxide; D013329:Structure-Activity Relationship; D014025:Titanium; D014639:Vanadium
chemical_list: D009587:Nitrogen Isotopes; D011522:Protons; D014639:Vanadium; C009495:titanium dioxide; D012822:Silicon Dioxide; D014025:Titanium