Characterization of chromium ion-doped titania by FTIR and XPS

Journal Article · Sun May 01 04:00:00 EDT 1994 · Journal of Catalysis; (United States)

DOI:https://doi.org/10.1006/jcat.1994.1121· OSTI ID:7197590

Venezia, A M; Schiavello, M ^[1]; Palmisano, L ^[2]; Martin, C; Martin, I; Rives, V ^[3]

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1. Universita di Palermo (Italy)
2. Universita della Calabria (Italy)
3. Universidad de Salamanca (Spain)

Chromium ion-doped polycrystalline titania catalysts, mainly used in photoreactions, were studied by Fourier transform infrared (FTIR) spectroscopy and by X-ray photoelectron spectroscopy (XPS). Two series of catalysts prepared by two different methods, i.e., coprecipitation and impregnation, were analyzed. The FTIR spectra recorded upon adsorption of ammonia and after outgassing at increasing temperatures indicated that Cr[sub x]O[sub y]/TiO[sub 2] samples, whichever preparation method was used, have two types of surface acid sites, Lewis and Bronsted sites. The Bronsted sites are associated with the presence of chromium, since they were not detected in pure titania. According to the X-ray photoelectron study, Cr(III) and Cr(VI) species are present in both series of catalysts, with the higher oxidation state being quite unstable under X-rays. As shown by quantitative XPS analysis, only the catalysts prepared by coprecipitation and containing up to 2% Cr can be described by the Kerkhof-Moulijn monolayer model. 24 refs., 7 figs., 1 tab.

• OSTI ID: 7197590
• Journal Information: Journal of Catalysis; (United States), Journal Name: Journal of Catalysis; (United States) Vol. 147:1; ISSN 0021-9517; ISSN JCTLA5
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
ABSORPTION SPECTROSCOPY
CHALCOGENIDES
CHROMIUM COMPOUNDS
CHROMIUM OXIDES
CRYSTAL DOPING
ELECTRON SPECTROSCOPY
OXIDES
OXYGEN COMPOUNDS
PHOTOELECTRON SPECTROSCOPY
SPECTROSCOPY
STRUCTURAL CHEMICAL ANALYSIS
TITANIUM COMPOUNDS
TITANIUM OXIDES
TRANSITION ELEMENT COMPOUNDS
X-RAY SPECTROSCOPY