Investigation of the Surface Structure and Activity of Molybdenum Oxide-Containing Catalysts I. An Infrared Study of the Surface Structure of Molybdena-Alumina Catalysts
نویسنده
چکیده
A comparison has been made of the infrared spectra of alumina with molybdenum oxide alumina in both the oxidized and reduced forms. In the case of molybdena-alumina prepared via adsorption of gaseous MoOp(OH)t, the spectra show that a practically complete monolayer of Mo6+ oxide covers the alumina. After reduction with hydrogen the hydroxyls of the carrier appear. From the reversibility of reduction and oxidation under mild conditions it has been established that the reduced oxide is present as an interrupted monolayer. Catalysts prepared by adsorption of molybdate ions from solution contain Al hydroxyls, due to a lower MO content.
منابع مشابه
Cobalt Loading Effects on the Structure and Activity for Fischer-Tropsch and Water-Gas Shift Reactions of Co/Al2O3 Catalysts
An extensive study of Fischer-Tropsch synthesis (FTS) on alumina-supported cobalt catalysts with different amounts of cobalt is reported. Up to 40 wt % of cobalt, is added to the catalysts by impregnation method. The effect of the cobalt loading on the reducibility of the cobalt oxide species, dispersion of the cobalt, average clusters size, water-gas shift (WGS) activity and activity and s...
متن کاملThe role of carburization temperature on the molybdenum carbide surface and their catalytic activity
The surfaces of molybdenum carbide were varied by changing the carburization temperature between 823 and 1123 K. The surfaces of the catalytic material were investigated using in-situ temperature program carburization followed by temperature program reduction and oxidation. In-situ temperature program oxidation (TPO) showed the surfaces of the catalysts contain a similar amoun...
متن کاملInvestigation of the Activity of Nano Structure Mn/γ-Al2O3 Catalyst for Combustion of 2-Propanol
This paper reports results of a study regarding the activities of nano structure Mn/γ-Al2O3 and γ-Al2O3 catalysts for oxidation of 2-propanol (as a model of volatile organic compound). Nanostructure of catalysts was revealed using XRD, SEM and TEM techniques. Catalytic studies were carried out in U-shaped packed bed reactor under atmospheric pressure and at the reaction temperature of 150- 500°...
متن کاملRaman and IR studies of surface metal oxide species on oxide supports : Supported metal oxide catalysts
Raman and infrared spectroscopy provide complementary information about the nature of the surface metal oxide species present in supported metal oxide catalysts. This paper reviews the type of fundamental information that is typically obtained in Raman and IR characterization studies of supported metal oxide catalysts. The molecular structures of the surface metal oxide species are reflected in...
متن کاملEffects of metal oxide catalysts on the photodegradation of antibiotics effluent
The current study examined the effect of metal oxide catalysts on the sorption and photocatalytic efficiencies for the removal of ciprofloxacin and ofloxacin in water. ZnO and TiO2 catalysts are prepared using a suitable method based on the sol-gel process, which have a great change in structural and textural properties. The structure and surface area of the synthesized catalysts wer...
متن کامل