Effect of the support on the surface composition of vanadium phosphate catalysts in the oxidative dehydrogenation of ethane

被引：8

作者：

Casaletto, MP

Lisi, L

Mattogno, G

Patrono, P

Ruoppolo, G

机构：

[1] CNR, Inst Nanostructured Mat, I-90146 Palermo, Italy

[2] CNR, Inst Res Combust, I-80125 Naples, Italy

[3] CNR, Inst Nanostructured Mat, I-00016 Monterotondo, RM, Italy

[4] CNR, Dept Inorgan Methodol, I-00016 Monterotondo, RM, Italy

来源：

SURFACE AND INTERFACE ANALYSIS | 2004年 / 36卷 / 08期

关键词：

XPS; vanadium phosphate catalyst; vanadium oxidation state; surface characterization; oxidative dehydrogenation of ethane;

D O I：

10.1002/sia.1751

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：

Vanadyl phosphate catalysts supported on different oxides (gamma-Al2O3, TiO2, SiO2) have been investigated by x-ray photoelectron spectroscopy (XPS). The surface chemical composition has been studied as a function of the thermal treatment under oxidizing (calcination) or reaction conditions in the oxidative dehydrogenation of ethane. Dispersion of vanadyl phosphates on gamma-Al2O3 and TiO2 results in the formation of vanadium species in different oxidation states, i.e. V5+ phosphate, V5+ and V4+ oxide species, whose relative fraction depends both on the support and on the reaction temperature. A progressive reduction of vanadium species occurs in the samples as an effect of the temperature. Vanadyl phosphates exhibit a stronger interaction with the titania support, which undergoes surface modifications after impregnation, thermal treatments and catalysis runs. A noticeable interaction of the alumina support and a poor dispersion of the active phase on silica are also revealed by XPS. Copyright (C) 2004 John Wiley Sons, Ltd.

引用

页码：737 / 740

页数：4

共 14 条

[1] Influence of the acid-base character of supported vanadium catalysts on their catalytic properties for the oxidative dehydrogenation of n-butane [J].