Transition metal oxides reaction with

Reaction with HX 4, 2,7.3.1 Reaction with ZnO 4, 2.8.15.2 Reaction with Be2C 4, 2,7.8 Reaction with transition-metal oxides 4,... 

Studies related to the mechanisms of nitric oxide reactions with transition metal complexes in this laboratory were supported by grants from the U.S. National Science Foundation, by a Collaborative UC/Los Alamos National Laboratory Research grant, by a grant from the U.S. Japan Cooperative Research Program (Photoconversion/ Photosynthesis) (NSF INT 9116346), and by a grant from the ACS Petroleum Research Fund. We thank the students and postdoctoral fellows at UC Santa Barbara who participated in this research and acknowledge collaborative studies with Dr. David Wink (National Cancer Institute, Bethesda MD, USA), Dr. Mikio Hoshino (RIKEN, Wako-shi, Japan) and Dr. Jon Schoonover (Los Alamos National Laboratory). 

The cyanide ion, CN, is isoelectronic with carbon monoxide and has an extensive chemistry of reaction with transition metals (e.g. the formation of the hexacyanoferrate(III) ion, [Fe(CN)63 ] by reaction with iron(III) in solution) but, unlike CO, it shows a preference for the positive oxidation states of the elements. This is mainly because of its negative charge. 

Although much of the biological literature focuses on nitrosating reactions of nitric oxide, chemically nitric oxide is a moderate one-electron oxidant, making formation of nitroxyl anion feasible under physiological conditions. The reduction potential to reduce nitric oxide to nitroxyl anion is +0.39 V, whereas it requires +1.2 V to oxidize nitric oxide to nitrosonium ion. Nitrosating reactions of nitric oxide are often mediated by conversion of nitric oxide to another nitrogen oxide species or by direct reaction with transition metals (Wade and Castro, 1990). 

A fundamental problem in characterizing metal surfaces in oxidation catalysis is that, as with transition metal oxides, the chemistry of the surface is shaped by the reaction conditions. Margolis has taken the plausible position that most metal surfaces in oxygen are covered with oxygen and behave like metal oxides (13, 14). This is true even of platinum, a classical example of a metal catalyst, and here again predictions from bulk thermodynamics are unreliable with respect to the surface. 

Luminescence Spectra from n-TiCh and n-SrTiCh Semiconductor Electrodes and Those Doped with Transition-Metal Oxides As Related with Intermediates of the Photooxidation Reaction of Water. Mechanistic aspects clarified using photo-and electroluminescence measurements. 407... 

New regulations in the United States and Europe mandate that automotive emissions must decrease substantially from current levels. As a result, there is a strong incentive to develop improved TWC with better oxidation activity at low temperatures since most of the hydrocarbons and CO are emitted immediately following cold starts of engines. As previously mentioned, the addition of transition metal oxides can have a beneficial effect on the performance of Au catalysts in CO oxidation. Combinations of Pt or Pd with transition metal oxides are also active in CO oxidation at low temperatures 50). Figure 11 shows examples of the reaction over Pt/MO/ Si02 catalysts. 

Only a few chalcogen halide adducts with oxide halides are known. In the course of a systematic study on exchange reactions of transition metal oxides with SCI2/CI2, paramagnetic [SCla JtMoOCU ] was obtained and characterized (157,241). 

Pillared interlayered clays (PILC) can be regarded as nanocomposites, in which oxide particles of nano- and subnanometer scales are incorporated into the interlayer space of two-dimensional aluminosilicates [1]. In recent years, much attention has been focused on this new type of materials with large heights of pillars, because they provide larger pores in comparison to conventional zeolites. Smectites pillared with transition metal oxides (e.g. Cr, Fe, Ti) are of particular interest because the incorporated phases have themselves catalytic properties. Such solids are claimed to possess a remarkable activity in a notable number of reactions [2,3]. 

Reactions of free radicals with molecules (or ions) can occur via an addition reaction, for instance the addition of a C-centered radical to oxygen (4.2), hydrogen atom abstraction (4.3), or electron transfer mechanism (e.g., oxidation of CO " by SO" ). Since the total number of electrons is odd, one of the products is a new radical (e.g., (4.2) and (4.3)), except for the reactions with transition metal ions, such as the oxidation of superoxide radicals by Fe3+ ions ... 

Transition metal ions dispersed in spinel matrices were studied for the decomposition of nitrous oxide (15,16) however, there have been no reports on solid solutions of spinels for augmenting catalytic activity and stability in oxidation reactions. This is a report on work done with transition metal oxide spinels to minimize the first two forms of degradation through formation of solid solutions. Included are studies of various reaction processes involved in catalytic treatment of automotive exhaust gases. 

Alkali oxides are thermodynamically stable up to very high temperatures, and even hydrides have saline character and considerable stability. Lithium nitride is a compound which can be isolated from the solution in the metal in crystalline form. Dissolved oxides have the ability to react with transition metal oxides to form complex oxides, or with hydrogen to form hydroxides of the heavier alkali metals. Lithium cyanamide is formed by means of the reaction between nitrogen and carbon dissolved in the molten metal. The reaction product in liquid sodium is sodium cyanide. 

Destmctive reaction of Cl-containing compounds with transition metal oxides supported on MgO or CaO has been smdied (12-14). The order of activity found for transition metals (V > Mn > Co > Fe > Ti > ) is similar to that for typical oxidation reactions. Another interesting finding by the same group was that the transition metals catalyze the exchange reaction between chloride and oxide ions (14). An intermediate metal chloride such as VClx may migrate over the MgO nanocrystal to assist the exchange of Cl with O. ... 

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