Effect of niobium on the surface properties of Nb2O5-SiO2-supported Mo catalysts

被引：38

作者：

Damyanova, S ^{[1
]}

Dimitrov, L

Petrov, L

Grange, P

机构：

[1] Bulgarian Acad Sci, Inst Catalysis, BU-1113 Sofia, Bulgaria

[2] Catholic Univ Louvain, Unite Catalyse & Chim Mat Divises, B-1348 Louvain, Belgium

来源：

APPLIED SURFACE SCIENCE | 2003年 / 214卷 / 1-4期

关键词：

Nb2O5-SiO2; oxides; molybdenum; acidity; dispersion; XPS;

D O I：

10.1016/S0169-4332(03)00347-7

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

Nb2O5-SiO2 oxides with different Nb content (0.8-4.4 wt.%) were prepared by impregnation of silica with ethanol solution of niobium ethoxide, Nb(OC2H5)(5). Mo catalysts supported on the Nb2O5-SiO2 carriers were prepared by wetness impregnation method of the supports with an aqueous solution of ammonium heptamolybdate, (NH4)(6)MO7O24. The samples were characterized by X-ray photoelectron spectroscopy (XPS) and diffuse reflectance spectroscopy (DRS). The chemical state and dispersion of metal components (Nb and Mo) were studied in the oxides and Mo-containing catalysts. It was shown a good correlation between the amount of Nb and XPS intensity Nb/Si ratios in oxide supports. Generation of new acid sites (Lewis and Bronsted) in Nb2O5-SiO2 samples was easily understood when considering the change in the binding energies of Nb 3d and 0 Is photoelectrons, due to a strong interaction between Nb atoms and silica. It was found that addition of niobium improves the dispersion of molybdenum on silica. (C) 2003 Elsevier Science B.V. All rights reserved.

引用

页码：68 / 74

页数：7

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