Molybdenum-niobium oxides

Litinskii et al. investigated the contact between the fluoropolymer SKF 32 (fluorine-containing rubber) and three oxide surfaces molybdenum oxide and solid solutions of molybdenum-niobium oxides and molybdenum-technetium oxide [115], Contact appeared when a bond was created between a metal atom and a carbon that lost its fluorine atom. Molecular orbitals on clusters simulating the contact between the fluoropolymer and the oxide surfaces have been computed using the DFT B3LYP/3-21g. Nine contacts between the three available metal atoms (molybdenum, niobium, and technetium) and the three carbon atoms of the fluoropolymer have been studied. Electronic spectra revealed that the molybdenum atom leads to the most favorable contact with the SKF 32 fluoropolymer. A similar analysis has been carried out with ferric and nickel oxides [116]. 

Manganese trichloride oxide, 4141 Mercury(I) oxide , 4613 Mercury(II) oxide, 4605 Molybdenum(IV) oxide, 4716 Molybdenum(VI) oxide, 4717 Nickel(II) oxide, 4821 Nickel(III) oxide, 4823 Nickel(IV) oxide, 4822 Niobium(V) oxide, 4818 Osmium(IV) oxide, 4833 Osmium(VIII) oxide, 4858 Palladium(II) oxide, 4825 Palladium(III) oxide, 4848 Palladium(IV) oxide, 4835... 

LEIS is most often carried out with a beam of helium ions, but when a catalyst contains heavier elements, it may be advantageous to use neon ions to distinguish better between the elements (see Fig. 4.13). Of course, elements with a mass smaller than neon cannot be detected in that case. Figure 4.20 illustrates this with He- and Ne-LEIS spectra of a multicomponent oxide catalysts containing vanadium, molybdenum, niobium and tellurium. These mixtures are of inter-... 

Beyond providing bulk structural information about 3-D metal oxide phases, Raman spectroscopy can also provide information about the terminating (and thus 2-D) surface layers of bulk metal oxides. For example, surface Nb=O, V = O, and Mo=O functionalities were detected by Raman spectroscopy for bulk Nb2Os, and for vanadium-niobium, molybdenum-vanadium, molybdenum-niobium, and vanadium-antimony mixed oxide phases (Guerrero-Perez and Banares, 2004 Jehng and Wachs, 1991 Zhao et al., 2003). 

Hence, the challenge remains to fully analyze the surface layers of bulk oxide catalysts. Recently, Zhao et al. succeeded for the first time in detecting surface MoO and VOv species on molybdenum-niobium and vanadium-niobium mixed metal oxides by Raman spectroscopy (Zhao et al., 2003). 

Oxidizer, Poison, Corrosive SAFETY PROFILE Poisonous and corrosive. Very reactive, a powerful oxidizer. Explosive or violent reaction with organic materials, water, acetone, ammonium halides, antimony, antimony trichloride oxide, arsenic, benzene, boron, bromine, carbon, carbon monoxide, carbon tetrachloride, carbon tetraiodide, chloromethane, cobalt, ether, halogens, iodine, powdered molybdenum, niobium, 2-pentanone, phosphoms, potassium hexachloroplatinate, pyridine, silicon, silicone grease, sulfur, tantalum, tin dichloride, titanium, toluene, vanadium, uranium, uranium hexafluoride. 

Stampfl et al. reported the formation of a surface molybdenum oxide phase upon thermal treatment of mixtures of M0O3 with tin oxide (Sn02). Vanadium oxide (V2O5) did not seem to spread on the surfaces of Sn02, niobium oxide (Nb205) and zirconium oxide (Z1O2) as concluded by Hdnicke and Xu. These authors did not specify the... 

The Structural Chemistry of Bismuth-Tungsten-Molybdenum Oxides and Bismuth-Tungsten-Niobium Oxides... 

Some metal oxide catalysts are activated by thermal reduction with hydrogen or carbon monoxide. For example, the catalytic activity of molybdenum oxide and tungsten oxide for the metathesis reaction of olefins is very much enhanced by their slight reduction (1). The catalytic activity for butene isomerization and ethene oligomerization appears on niobium oxide by its... 

Lithium hydroxide Lithium hydroxide monohydrate 215-185-5 AS-9600 DWS 1016 DWS 1017A pHreeGUARD 1215C pHreeGUARD 2350 Sodium hydroxide Unichem SOHYD 215-193-9 Indium oxide 215-197-0 Potassium sulfide 215-199-1 Potassium silicate Trasol KA-L Trasol KA-N Trasol KC-K Trasol KD-K 215-200-5 Lanthanum oxide 215-202-6 Manganese dioxide 215-204-7 Charmax MO Molybdenum trioxide Molyhibit POM POC Polu-U 215-208-9 Sodium oxide 215-211-5 Sodium polysulfide Sodium sulfide 215-213-6 Niobium oxide 215-215-7 Nickel oxide (ous)... 

A timeline for the development of olefin metathesis, adapted from a review by Grubbs, is shown in Figure 21.3. Olefin metathesis is more than 50 years old. " It was first conducted with ill-defined rhenium, molybdenum, and tungsten systems generated from perrhenate, aluminum oxide, - and tetraethyl lead as additive, from molybdenum oxide on p-TiO and tetramethyltin as additive, ° or from tungsten phenoxides supported on niobium oxide and silicon oxide activated with alkylaluminum reagents. The temperatures for these processes are hi, but the catalysts are relatively inexpensive and can be long lived. These are the types of catalysts that have been used for the synthesis of commodity chemicals by olefin metathesis. 

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