On the nature of highly dispersed vanadium oxide catalysts: Effect of the support on the structure of VO(x) species

FERREIRA, M.L.; VOLPE, M.

JOURNAL OF MOLECULAR CATALYSIS A-CHEMICAL

ELSEVIER SCIENCE BV

Año: 2000 vol. 164 p. 281 - 290

1381-1169

The nature of VO(x) specie supported on TiO2, γ-Al2O3 and SiO2 is analyzed. The plausibility of different VO(x) specie (mono, di, pyrovanadates) is evaluated by means of a theoretical study of the extended Huckel (EH) type. Theoretical results are compared with published characterization data and discussion is performed taking account both results. The interaction of VO(x) with the support and the structure of supported surface vanadia are influenced by the composition of the oxide carder. On SiO2, only the monovanadate species are formed. On γ-Al2O3, dimers seem to be the more plausible supported form of VO(x). On TiO2, monomers and dimers are present; however, the latter species being the most abundant. (C) 2000 Elsevier Science B.V.