Occurrence, Extraction, Production and uses of Molybdenum
About: This article is published in Studies in Inorganic Chemistry.The article was published on 1994-01-01. It has received 10 citations till now. The article focuses on the topics: Extraction (chemistry) & Molybdenum.
Citations
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TL;DR: In this article, a density functional theory (DFT) analysis of the O 2sp dominated valence band region of MoO 3 was carried out to examine the electronic structure of the oxide systems.
156 citations
TL;DR: In this paper, the structure and electronic properties of the α-MoO3 were studied with periodic LAPW calculations with the results in excellent agreement with the reported experimental pseudo-cubic results.
41 citations
TL;DR: In this paper, the authors performed cluster model studies by means of ab initio DFT method to examine electronic properties of different surface O atoms in several V2O5 and MoO3 systems and correlate them with catalytic behavior.
27 citations
TL;DR: In this paper, the electronic properties of MoO 2 bulk and (0, 1, 1) surface are discussed. But the surface retains the metallic character of the bulk, and it is found that Fermi level is located within the band dominated by d molybdenum orbitals.
Abstract: Electronic properties of MoO 2 bulk and (0 1 1) surface are discussed. It is found that Fermi level is located within the band dominated by d molybdenum orbitals, thereby reflecting the metallic character of the system. Results for (0 1 1)MoO 2 surface indicate that the surface retains the metallic character of the bulk. Depending on the thickness of the slab used to model the surface (1-layer or 2-layers) the electronic structure and properties change. In the 2-layer slab, bands close to the Fermi level originate both from regular six-fold coordinated Mo(6) centers as well as from five-fold coordinated Mo(5) centers occurring due to surface formation. In the 1-layer slab, peaks right below the Fermi level are dominated by the surface centers that are six-fold coordinated Mo(6) but also centers which are effectively four-fold coordinated Mo(4). This has a profound effect on the reactivity as was tested by a probe reaction of H 2 adsorption, which did not interact with the surface described by the 2-layer slab, but underwent dissociation on the 1-layer slab. The Mo–Mo pairs with bonds of approximately single character, characteristic for the bulk structure, are also present on the surface, both on 1-layer and 2-layer slabs. The local properties of (0 1 1)MoO 2 surface are very similar to other transition metal oxides. Metal–oxygen bonds are of a mixed ionic and covalent nature and the nucleophilicity of oxygen increases with the increase of coordination numbers of the corresponding oxygen atoms.
26 citations
TL;DR: In this article, the atomic structure of a reconstructed Mo(1/1/2)-O(2/2/3) surface has been revisited using photoelectron spectroscopy with synchrotron radiation, scanning tunneling microscopy, infrared reflection absorption spectrography and density functional theory.
22 citations
References
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TL;DR: In this article, the reaction layers formed under Reichert wear test conditions in the presence of four different extreme pressure additives and hence to determine the wear prevention mechanism was found to correlate with the formation of a thin, sulphur-rich reaction layer in the worn surface.
19 citations
TL;DR: Oxygen index results for a series of unsaturated polysters, containing molybdenum oxide and various halogenated compounds, have provided definite evidence for some form of flame retardant synergistic effect between MDE and halogen.
Abstract: Oxygen index results for a series of unsaturated polysters, containing molybdenum oxide and various halogenated compounds, have provided definite evidence for some form of flame retardant synergistic effect between molybdenum and halogen. With the halogenated compounds used, the magnitude of the effect was greater in the presence of bromine but was dependent on the type of compound. When dibromoneopentyl glycol was used as the bromine source, the synergistic effect exhibited by molybdenum oxide was comparable to that shown by antimony oxide. Since molybdenum oxide also acts as a smoke suppressant, it could offer a useful alternative to antimony oxide particularly in the light of probable changes in standards and regulatory control regarding smoke emission.
19 citations
TL;DR: The degree of bond breaking and structural rearrangements which occur has an important influence on the utility of such reactions for electrochemical energy storage as discussed by the authors. But the degree of break and rearrangement depends on the type of the chalcogenides.
17 citations
TL;DR: In this article, the occurrence of lower valency ions in molybdate films has been attributed to a possible electrochemical reduction process, and the incidence of inflections on the cathodic polarisation curve for tin and zinc in chromate, moly bdate and tungstate solutions has been examined.
Abstract: The incidence of inflections on the cathodic polarisation curve for tin and zinc in chromate, molybdate and tungstate solutions has been examined. The occurrence of lower valency ions in molybdate films has been attributed to a possible electrochemical reduction process.
17 citations
17 citations