Oxygen formation

The alkali chlorates melt before decomposition [844], The catalytic properties of Co304 in promoting [865] the solid phase decomposition of NaC103 are attributed to the ability of the oxide to donate an electron to an oxygen atom, temporarily accepted at its surface from a CIO ion, prior to molecular oxygen formation and desorption. The progressive increase in E during reaction (from 120 to 200 kJ mole-1) is associated with systematic deactivation of the surface. 

A.van Oertzen, A. Mikhailov, H.-H. Rotermund, and G. Ertl, Subsurface oxygen formation on the Pt(l 10) surface experiment and mathematical modeling, Surf. Sci. 

AO. For oxygen formation during the decomposition of NO2 Rate of production of O2 =... 

On the other hand, carbonyl quenching by polyenyl radicals in PVC has been invoked in order to account for autoinhibition during photooxidative degradation (52). Some workers have mentioned the possibility of singlet oxygen formation in PVC via the quenching of excited polyenes (25,29) or cyclohexadienes (53). 

The matrix photochemistry of 2v proved to be fairly complicated.108 The primary product of the photolysis of 2v is carbene lv, which was identified by ESR spectroscopy. Under the conditions of matrix isolation the carbene showed the expected reactivity towards molecular oxygen (formation of carbonyl oxide 7v) and carbon monoxide (formation of ketene lOv) (Scheme 22). In contrast to the oxocyclohexadienylidenes (la and derivatives) carbene lv slowly reacted with CO2 to give an a-lactone with the characteristic C=0 stretching vibration at 1896 cm-1. The latter reaction indicates that lv is — as expected — more nucleophilic than la. 

Rice, C.D. and B.A. Weeks. 1990. The influence of in vivo exposure to tributyltin on reactive oxygen formation in oyster toadfish macrophages. Arch. Environ. Contam. Toxicol. 19 854-857. 

Ether Air (oxygen) Formation of explosive organic peroxides... 

Hu and Ruckenstein s results (130) showed that on the reduced nickel-containing catalyst, the reaction took place by a Langmuir-Hinshelwood mechanism involving adsorbed CH4 and oxygen species. Furthermore, they indicated that a slow dynamic redox process consisting of lattice oxygen formation and its reduction by carbon species was at least partly responsible for the CO formation. 

Fischer-Tropsch catalysis, 34 71, 38 331-335 C2 oxygenate formation, 38 338 oxide-supported osmium clusters, 38 335 product selectivites, 38 333-334 proton-induced reduction of CO, 38 332-333... 

Chemical/Physical. Anticipated products from the reaction of 1,4-dioxane with ozone or OH radicals in the atmosphere are glyoxylic acid, oxygenated formates, and OHCOCH2CH2OCHO (Cupitt, 1980). Storage of 1,4-dioxane in the presence of air resulted in the formation of 1,2-ethanediol monoformate and 1,2-ethane diformate (Jewett and Lawless, 1980). Stefan and Bolton... 

The amperometric immunosensors reported so far rely on various methodological principles including use of a Clark electrode for detecting oxygen formation or depletion, an electrochemically active product yielded in an enzyme reaction or an antigen labelled with an electroactive species. 

SCHEME 11. Mechanism for the singlet-oxygen formation in the catalytic decomposition of Caroate by ketones... 

Acetic acid has been generated directly from synthesis gas (CO/H2) in up to 95 wt % selectivity and 97% carbon efficiency using a Ru-Co-I/Bu4PBr "melt" catalyst combination. The critical roles of each of the ruthenium, cobalt and iodide catalyst components in achieving maximum selectivity to HOAc have been identified. Ci Oxygenate formation is observed only in the presence of ruthenium carbonyls [Ru(C0)3l3] is here the dominant species. Controlled quantities of iodide ensure that initially formed MeOH is rapidly converted to the more reactive methyl iodide. Subsequent cobalt-catalyzed carbonylation to acetic acid may be preparatively attractive (>80% selectivity) relative to competing syntheses where the [00(00)4] concentration is optimized that is, where the Co/Ru ratio is >1, the syngas feedstock is rich in 00 and the initial iodide/cobalt ratios are close to unity. 

This suggests that formyl species are key intermediates both to hydrocarbons and to oxygenates. The first part of the mechanism for oxygenates formation would be the same as in methanol synthesis. 

Molecular oxygen formation is probably negligible at all but the highest LET and HO2 can be normally ignored with fast electrons and y-rays. 

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