Transition iron oxides

Alkali metal haHdes can be volatile at incineration temperatures. Rapid quenching of volatile salts results in the formation of a submicrometer aerosol which must be removed or else exhaust stack opacity is likely to exceed allowed limits. Sulfates have low volatiHty and should end up in the ash. Alkaline earths also form basic oxides. Calcium is the most common and sulfates are formed ahead of haHdes. Calcium carbonate is not stable at incineration temperatures (see Calcium compounds). Transition metals are more likely to form an oxide ash. Iron (qv), for example, forms ferric oxide in preference to haHdes, sulfates, or carbonates. SiHca and alumina form complexes with the basic oxides, eg, alkaH metals, alkaline earths, and some transition-metal oxidation states, in the ash. 

Co304 with an excess of n-butyl lithium results in further lithiation of the oxide particles, but with a concomitant extrusion of very finely divided transition metal from the rock salt structure. Highly lithiated iron oxide particles are pyrophoric if exposed to air [100]. 

The reduction of a transition-metal oxide and boron oxide by an electropositive metal such as Al, Mg or an alkali metal has been used as a pathway to titanium, iron, chromium, tungsten and alkali-earth borides . ... 

The stoichiometry of transition metal oxides is more variable. Iron, for example, forms three binary oxides. In FeO the iron atoms have lost two electrons each (Fe, O ), and in Fc2 O3 they have lost three electrons each... 

Methane-to-methanol conversion by gas-phase transition metal oxide cations has been extensively studied by experiment and theory see reviews by Schroder, Schwarz, and co-workers [18, 23, 134, 135] and by Metz [25, 136]. We have used photofragment spectroscopy to study the electronic spectroscopy of FeO" " [47, 137], NiO [25], and PtO [68], as well as the electronic and vibrational spectroscopy of intermediates of the FeO - - CH4 reaction. [45, 136] We have also used photoionization of FeO to characterize low lying, low spin electronic states of FeO [39]. Our results on the iron-containing molecules are presented in this section. 

The real part is the magnetic permeability whereas the imaginary part is the magnetic loss. These losses are quite different from hysteresis or eddy current losses, because they are induced by domain wall and electron-spin resonance. These materials should be placed at position of magnetic field maxima for optimum absorption of microwave energy. For transition metal oxides such as iron, nickel, and cobalt magnetic losses are high. These powders can, therefore, be used as lossy impurities or additives to induce losses within solids for which dielectric loss is too small. 

Brezesinski, T. Groenewolt, M. Antonietti, M. Smarsly, B. 2006. Crystal-to-crystal phase transition in self-assembled mesoporous iron oxide films. Angew. Chem. Int. Ed. 45 781-784. 

Ford, R.G., Bertsch, P.M., Farley, K.J. 1997. Changes in transition and heavy metal partitioning during hydrous iron oxide aging. Environmental Science and Technology, 31, 2028-2033. 

This work summarizes some applications of in situ Mossbauer spectroscopy to the study of certain aspects of the electrochemistry of iron and iron containing transition metal oxides. A number of illustrations of the use of this technique to the investigation of a wide variety of interfacial phenomena may be found in two recent monographs. (2 ... 

Few studies have systematically examined how chemical characteristics of organic reductants influence rates of reductive dissolution. Oxidation of aliphatic alcohols and amines by iron, cobalt, and nickel oxide-coated electrodes was examined by Fleischman et al. (38). Experiments revealed that reductant molecules adsorb to the oxide surface, and that electron transfer within the surface complex is the rate-limiting step. It was also found that (i) amines are oxidized more quickly than corresponding alcohols, (ii) primary alcohols and amines are oxidized more quickly than secondary and tertiary analogs, and (iii) increased chain length and branching inhibit the reaction (38). The three different transition metal oxide surfaces exhibited different behavior as well. Rates of amine oxidation by the oxides considered decreased in the order Ni > Co >... 

The interaction and sorption of metal ions with metal oxide and clay surfaces has occupied the attention of chemists, soil scientists, and geochemists for decades (1-4). Transition metal oxides receiving particular emphasis have included various oxides of manganese and iron (5). Interest in sorption phenomena is promoted by the desire to better understand incorporation of metals into minerals, especially marine deposits ( ), the removal of trace metal pollutants and radionuclides from rivers and streams, via sorption and/or precipitation phenomena (1,6), and the deposition of metals on solid substrates in the preparation of catalysts (7,8). 

Researchers estimate that known reserves of industrially important transition metals, such as manganese and iron, will be depleted in less than a human lifetime. Scattered about the ocean floor are billions of tonnes of small chunks of rock ranging in diameter from several millimetres to several metres. These nodules, as they are called, consist mainly of manganese and iron oxides, but contain smaller amounts of other transition-metal compounds as well. The ocean floor is designated as international property. Therefore, no single country may claim ownership of this vast potential resource. Write an editorial that outlines your recommendations for how this resource may be shared. 

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