STRUCTURE OF MOO3/AL2O3-SIO2 CATALYSTS

被引：51
作者：
HENKER, M
WENDLANDT, KP
VALYON, J
BORNMANN, P
机构：
[1] TECH UNIV MERSEBURG, DEPT CHEM, O NUSCHKESTR, W-4200 MERSEBURG, GERMANY
[2] HUNGARIAN ACAD SCI, CENT RES INST CHEM, H-1361 BUDAPEST 5, HUNGARY
[3] LEUNA WERKE AG, DEPT CATALYSIS, W-4201 LEUNA, GERMANY
来源：
APPLIED CATALYSIS | 1991年 / 69卷 / 02期
关键词：
MOLYBDENUM OXIDE ALUMINA-SILICA; CATALYST CHARACTERIZATION (IR; UV-VIS; XRD); ACIDITY;
D O I：
10.1016/S0166-9834(00)83303-5
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：
The structure of MoO3/Al2O3-SiO2 mixed oxide catalysts was studied by XRD, IR and UV-Vis spectroscopy. The nature of the Mo-O species formed depends on the composition of the amorphous Al2O3-SiO2 and is controlled by the inhomogeneity of the Al2O3-SiO2 carrier and the strong fixation of the molybdena on the separate alumina phase. The molybdenum is preferentially bound in the form of polymolybdates in the case of alumina-rich samples and as heteropolymolybdates or Al2(MoO4)3 in the case of silica-rich samples. The formation of heteropolymolybdates or Al2(MoO4)3 is due to the thermal instability of the amorphous Al2O3-SiO2. Introduction of molybdena generates new Bronsted acid sites on the surface of alumina-rich Al2O3-SiO2 supports. On the other hand no changes in Bronsted acidity induced by the molybdena has been found in catalysts with medium and low amounts of alumina.
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页码：205 / 220
页数：16
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