ISSN:
1572-879X
Keywords:
TiO2-Al2O3
;
Mo/Al2O3
;
Mo/TiO2-Al2O3
;
temperature programmed reduction (TPR)
;
X-ray photoelectron spectroscopy (XPS)
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
Notes:
Abstract The effect of TiO2 modified Al2O3 surface on the reducibility of MoO3 has been studied by TPR and XPS. The results show that Mo6+ in Mo/TiO2-Al2O3 can be reduced to much lower valency, especially at low Mo loading. The influence of the calcination temperature on the reduction of Mo6+ on Al2O3 and TiO2-Al2O3 carriers is different. The data reveals that the reducibility of Mo6+ on Al2O3 slightly decreased, while that on TiO2-Al2O3 increased when the calcination temperature was raised. It is suggested that the stronger tetrahedral site of the Al2O3 surface was first occupied by TiO2 and main octahedral Mo6+ in polymeric species-; and a small crystalline MoO3 formed on TiO2-Al2O3, whereas the formation of tetrahedral Mo6+ species and Al2(MoO4)3 phase was inhibited.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00764329
