3D-Transition Metal Oxides

This structure is commonly adopted by oxides, nitrides halides, and sulfides MX, including the nonstoichiometric 3d transition-metal oxides TiO, VO, MnO, FeO, CoO, and NiO. 

Relatively strong satellites, 5—10 eV from the main peaks, have been observed in the metal 2p spectra of 3d transition metal oxides and halides. These satellites... 

Synthesis, Characterisation and Applications of 3D Transition Metal Oxide Nano Particles... 

The focus of this paper is on the role electronic structure plays in determining the site preference and mobility of 3d transition-metal ions in an oxide and how these factors in turn affect the resistance of metastable 3d transition-metal oxides against transformation. This is a relevant topic to the Li rechargeable battery field because 3d transition-metal oxides are often used as positive electrode materials. 

As for the complete oxidation of propene, propane and methane, Nieuwenhuys and coworkers studied the influence of metal oxides additives on the catalytic activity of Au/Al203 [109-115], The addition of 3d transition metal oxides (MnOx, CoOx or FeOx), which were active by themselves, or ceria that was poorly active by itself promoted the catalytic activity of Au/Al203 in the total oxidation of propene [112]. The most active catalyst was Au/Ce0x/Al203, with a T95 at 497 K and with a high stability. In these cases, ceria and the transition metal oxides may act as co-catalysts and the role is twofold it stabilizes the Au NPs against sintering (ceria)... 

Figure 12. Comparison of old generation TEM-spectrometer typical spectrum (top) with new generation TEM-spectrometer spectrum (bottom). (Reprinted from Ultramicroscopy 96, Mitterbauer C., Kothleitner G., Grogger W., Zandbergen FL, Freitag B., Tiemeijer P and Hofer F., Electron energy-loss near-edge structures of 3d transition metal oxides recorded at high-energy resolution, 469-480, Copyright (2003) with permission from Elsevier)...

Leapman et al. (159, 160) have examined the general features (threshold energies, widths, and intensity ratios) of L1UI white lines in 3d transition-metal oxides (Ti02, Cr203, FeO, NiO, CuO), which arise from transition into a partially filled, large d density of states the relative white-line intensities remain as yet unexplained. 

Figure 7.2. The onsite d-d Coulomb repulsion energy (left) and the charge transfer excitation energy (right) for the 3d transition metal oxides. Plots are from data by Bocquet et al. (1992, 1996).

Periodic Trends in 3d Transition Metal Oxide Reactivity... 

The 3d transition metals are widely employed as catalyst and catalyst support materials in industry [3]. To gain insight into how these support materials and the catalyst support interaction influence catalytic activity, GIB-MS experiments were undertaken in our laboratory to determine the structural characteristics of cobalt oxide and nickel oxide clusters as well as their reactivity with CO. CID experiments were conducted employing Xe gas to elucidate the structural building blocks of the larger clusters. These studies provided insight into how additional (i-electrons impact the dissociation pathways and bonding motifs of 3d transition metal oxide clusters. Reactivity studies with CO were carried out, which revealed that oxide clusters composed of different 3d metals have specific stoichiometries which are most active for CO oxidation. 

Key words X-ray Absorption Spectra/3d-Transition Metal Oxides/SOFS-Cathodes MaterialsA alence State/Doped Lanthanum Manganite... 

The evaluation of elements valences (charge state of an atom in compound with the ionic type of chemical bond) is especially needed for studying and designing such materials as mixed valence semiconductors based on 3d-transition metal oxides. The preliminary set electron or hole current carrier density in such materials can be created by applying the valence regulation method. Such electroconducting oxide materials are widely used as electrodes of fuel cells and other current sources, gas sensors, electric heating elements, thermistors etc. 

It is the complex interplay among the many properties described above that spawns the diversity of phenomena observed in the 3d transition metal oxides. 

Krivanek, O.L. and Paterson, J.H. ELNES of 3d transition-metal oxides 1. Variations across the periodic table. Ultramicroscojiy 1990,32,313-318. Pease, D.M., Bader, S.D., Brodsky, M.B., Budnick, J.I., Morrison, T.L, and Zaluzec, N.J. Anomalous L3/L2 white line ratios and spin pairing in 3d transition metals and alloys Cr metals and Cr2oAugo- Phys. Lett 1986,114A, 491 94. 

Lenglet, M. Spectroscopic study of the chemical bond in 3d transition metal oxides. Correlation with the ionic-covalent parameter. Trends Chem. Phys. 1997, 6, 121-543. 

This chapter provides the relationships between structural and electrochemical properties of lamellar compounds the 3d-transition metal oxides currently studied as for their potential use in LiBs. First, we examine briefly three binary layered oxides, M0O3, V2O5, and LiVsOg which were proposed as intercalation compounds since at the end of 1970s. Then, the ternary layered oxides are considered. Starting from the historical and prototype compound LiCo02, which is the dominant positive electrode material employed by all Li-ion cell manufacturers so far, we state the broad family of layered oxides such as LiM Oy and their derivatives the... 

Table 6.3 Comparison of Ihe electrode characteristics of srane 3d transition-metal oxides...

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