Chemical composition mixed metal oxides

The existence of additional occupied states of Mo character, located above the O 2sp derived valence region, is relevant for the interpretation of experimental photoemission spectra of molybdenum oxide surfaces. According to the results of the cluster studies additional photoemission intensity above the valence band region may be indicative of chemical reduction of the metal centers, leading to lower oxidation states, where the effect can be introduced by oxygen vacancies or by different chemical composition of the oxide. This has been verified in UPS experiments on differently prepared MoOsCOlO) surfaces in comparison with measurements of other single and mixed valency molybdenum oxide samples [212]. 

Catalysts employed in the oxidative production of PA are V205-based compositions which are generally of the monolayer type and are supported on titania (anatase). With such catalysts, selectivities in excess of 80 mole % PA are achieved at essentially complete conversion. The utilization of Sb-V-oxidc-based catalysts supported on anatase improves the PA selectivity. However, little is known about the intrinsic chemical or electronic effects of Sb203 in such catalytic systems, as well as the chemical and physical characterization of the supported Sb-oxide or supported Sb-V-mixed metal oxide [1]. 

Preparation of mixed metal oxide precursors for SOFCs represents a very complex chemical process in which a metal may form oxides, hydroxides, and various complex basic salts as intermediates. Understanding of the relationship between the calcination process, the final composition, particle sizes, sinterability, and SOFC performance for nickel, copper and cobalt-based anode materials is a necessity [26]. 

Further inspection of Table 1-1, ho vever, reveals a selection of high performance pigments classified according to their chemical composition. In particular, the families of complex (or mixed) metal oxides, and functional pigments shoiv a ivide variety in their chemical composition. 

Based on the concept of mixed-framework lattices, we have reported a novel class of hybrid solids that were discovered via salt-inclusion synthesis [4—7]. These new compounds exhibit composite frameworks of covalent and ionic lattices made of transition-metal oxides and alkali and alkaline-earth metal halides, respectively [4]. It has been demonstrated that the covalent frameworks can be tailored by changing the size and concentration of the incorporated salt. The interaction at the interface of these two chemically dissimilar lattices varies depending upon the relative strength of covalent vs. ionic interaction of the corresponding components. In some cases, the weak interaction facilitates an easy... 

There are two main types of alumina (bauxite) ores used as the primary sources for aluminum metal and aluminum chemicals aluminum hydroxide [Al(OH)3] (gibbsite) and a mixed aluminum oxide hydroxide [AIO(OH)] (boehmite). Thus, bauxite is a term for a family of ores rather than a substance of one definite composition. An average composition of the ores used by industry today would be alumina (A1203), 35 to 60% silica (Si02), 1 to 15% ferric oxide (Fe203), 5 to 40% and titanium dioxide (Ti02), 1 to 4%. 

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