Transition Metal Oxides
Mostrando 1-12 de 20 artigos, teses e dissertações.
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1. ESTRATÉGIAS E MATERIAIS UTILIZADOS EM FOTOCATÁLISE HETEROGÊNEA PARA GERAÇÃO DE HIDROGÊNIO ATRAVÉS DA FOTÓLISE DA ÁGUA
Among the various technologies for the production of hydrogen fuel, heterogeneous photocatalysis is one of the most promising, especially with the use of semiconductors, notably TiO2. However, the use of TiO2 is limited by hindrances for the photolysis of water, such as wide bandgap, a less negative conduction band reduction potential as compared to that of
Quím. Nova. Publicado em: 2017-06
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2. Síntese e estudo da atividade eletrocatalítica de óxidos de metais de transição e de nanopartículas de prata e ouro para a reação de redução de oxigênio / Synthesis and study of the electrocatalytic activity of transition metal oxides, and silver and gold nanoparticles for the oxygen reduction reaction
The oxygen reduction reaction (ORR) was studied on electrocatalysts composed by pure and mixed transition metal oxides of Mn, Co, and Ni, including spinel-like structures, and by Ag, Au, and Ag3M/C (M= Au, Pt, Pd e Cu) bimetallic nanoparticles, in alkaline electrolyte. The transition metal oxides were synthesized by thermal decomposition of their nitrates, a
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 10/08/2011
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3. Investigation of structural, electronic and magnetica properties of Ca2-xLaxFelrO6, Sr2-xLaxFelrO6 e TbMnO3 oxides / Investigação as propriedades estruturais, eletronicas e magneticas dos oxidos Ca2-xLaxFelrO6, Sr2-xLaxFelrO6 e TbMnO3
For many decades the transition metal oxides are subject of great scientific interest because of the wide variety of interesting physical properties and their potential technological applications. More recently, for example, oxides of transition metals with multiferroic properties have been considered as potential magneto-electronic devices. Many transition
Publicado em: 2010
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4. Nanocomposites materials generated from a spray
The Spray Pyrolysis (SP) process has been employed at moderate temperature (470-970 K) for the synthesis of micro- and nano-particles of hydrated metal oxides and of related nanocomposites. It has been applied to iron nitrate solutions, without or with the addition of sodium chloride as a flux. After removal of the flux, nanocomposites of ferrihydrite (5Fe2O
Brazilian Journal of Physics. Publicado em: 2009-04
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5. Lanthanum based high surface area perovskite-type oxide and application in CO and propane combustion
The perovskite-type oxides using transition metals present a promising potential as catalysts in total oxidation reaction. The present work investigates the effect of synthesis by oxidant co-precipitation on the catalytic activity of perovskite-type oxides LaBO3 (B= Co, Ni, Mn) in total oxidation of propane and CO. The perovskite-type oxides were characteriz
Eclética Química. Publicado em: 2009
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6. Filmes automontados de óxidos metálicos: eletrocromismo e armazenamento de energia / Self-Assembled films composed of transition metal oxides for electrochromism and charge storage
Thin films of titanium dioxide (TiO2), poly(vinyl sulfonic acid) (PVS) and tungsten oxo-hydroxy (WOxHy) were prepared using the Layer-by-Layer (LbL) method, allowing for strict control of its thickness and nanoarchitecture. The properties of these films concerning lithium ion transport and storage were investigated, so that these materials can be applied in
Publicado em: 2009
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7. Catalisadores à base de Cu, Co ou Fe trocados ou suportados em zeólita USY avaliação na redução de NO com CO
The emissions of the nitrogen oxides (NOx) must be hardly reduced in the next years. The catalytic reduction of NO with CO is one of the possible processes with potential to be able to transform those oxides in N2. In that process, supported noble metals have been the most used, however, their low stability in the presence of water steam or SO2, have led to
Publicado em: 2008
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8. Estudo da oxidação total do etanol usando óxidos tipo perovskita LaBO3 (B= Mn, Ni, Fe)
The present work investigated the effect of coprecipitation-oxidant synthesis on the specific surface area of perovskite-type oxides LaBO3 (B= Mn, Ni, Fe) for total oxidation of ethanol. The perovskite-type oxides were characterized by X-ray diffraction, nitrogen adsorption (BET method), thermogravimetric analysis (TGA-DTA), TPR and X-ray photoelectron spect
Química Nova. Publicado em: 2007-10
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9. Síntese e caracterização de catalisadores de LaNiO3 não suportados e suportados em Al2O3 e ZrO2 para a reforma a vapor do metano
Ionic oxides with ABO3 structure, where A represents a rare earth element or an alkaline metal and B is a transition metal from group VIII of the periodic table are potential catalysts for oxidation and good candidates for steam reforming reaction. Different methods have been considered for the synthesis of the oxide materials with perovskite structure to pr
Publicado em: 2007
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10. SIMULAÇÕES ATOMÍSTICAS EM TRIFLUORETOS (REF3) E ÓXIDOS METÁLICOS MISTOS (RE(TiTa)O6) DE TERRAS-RARAS / ATOMISTIC SIMULATIONS IN TRIFLUORIDES (REF3) AND MIXED METAL OXIDES (RE (TiTa) O6) OF RARE-EARTH
In this work static atomistic simulations were performed to investigate two systems: rare-earth triuorides, REF3, with tysonite structure (RE = La, Ce, Pr and Nd) and rare-earth mixed metallic oxides, RE(TiTa)O6, with RE = Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Y, Er and Yb. In the rare-earth triuorides was investigated the pressure induced structural phase tra
Publicado em: 2006
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11. Nanotubos e nanobastões de oxidos e sulfetos de metais de transição obtidos via sistemas bidimensionais (lamelares) : preparação, caracterização e propriedades / Nanotubes and nanorods of transition metal oxides and sulfides obtained from bidimensional systems (layered compunds) : preparation, characteization and properties
This Thesis reports the preparation, characterization and properties of nanotubes and nanorods of transition metal oxides and sulfides obtained from bidimensional (Iamellar) structures. From the structural point view, nanotubes could be formed from bidimensional compounds by rolling its layers generating scroll-like nanotubes, or by the elimination of dangli
Publicado em: 2006
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12. Magnetic, thermal and spectral behaviour of 3-chloro-2-nitrobenzoates of Co(II), Ni(II), and Cu(II)
Physico-chemical properties of 3-chloro-2-nitrobenzoates of Co(II), Ni(II) and Cu(II) were synthesized and studied. The complexes were obtained as mono- and dihydrates with a metal ion to ligand ratio of 1 : 2. All analysed 3-chloro-2-nitrobenzoates are polycrystalline compounds with colours depending on the central ions: pink for Co(II), green for Ni(II) an
Eclética Química. Publicado em: 2006