Mixed Oxides
Mostrando 1-12 de 70 artigos, teses e dissertações.
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1. Enhanced Catalytic Performance of Strontium-Doped Lanthanum Manganites by the Presence of Molybdenum Oxides for Electro-Reduction of Hydrogen Peroxide
In this work, two catalysts, lanthanum manganite strontium-doped perovskite without (LSM) and with (LSMMO) mixed molybdenum oxides, were synthesized by the sol-gel route and deposited by immersion in carbon cloth substrates. Their performance as cathodes in the hydrogen peroxide reduction reaction (HPRR) and oxygen reduction reaction (ORR) was investigated t
Journal of the Brazilian Chemical Society. Publicado em: 2022
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2. Análises de dosagens de concreto asfáltico do tipo Pré Misturado a Frio (PMF) utilizando Resíduos da Construção e Demolição de obras (RCD)
RESUMO Na construção civil, um problema ambiental recorrente é a geração e disposição de Resíduos de Construção e Demolição (RCD) de obras. A utilização do RCD como agregados na composição de concreto asfáltico, do tipo Pré Misturado a Frio (PMF), torna possível a execução de pavimentos rodoviários de baixo tráfego. Diante desses fatos
Matéria (Rio J.). Publicado em: 25/11/2019
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3. CHARACTERIZATION-PERFORMANCE OF ZnO AND ZnO/ZnFe2O4 CATALYST USING ARTIFICIAL AND SOLAR LIGHT FOR MERCURY (II) REDUCTION
Abstract This study describes the application of ZnO commercial oxide and ZnO/ZnFe2O4 mixed oxides to reduce the mercury ion (Hg2+) in the aqueous phase. The catalysts synthesized were characterized by thermogravimetric analysis, adsorption and desorption of N2, scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, photoac
Braz. J. Chem. Eng.. Publicado em: 30/09/2019
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4. Estudo de obtenção da membrana cerâmica densa BaCeO3
RESUMO Nos últimos anos, pós cerâmicos à base de óxidos de estrutura do tipo perovskita ganharam atenção considerável devido às suas aplicações tecnológicas na área de membranas permeáveis de oxigênio. O óxido misto BaCeO3 apesenta-se como um material amplamente estudado em uma grande diversidade de aplicações, seja como materiais eletrolí
Matéria (Rio J.). Publicado em: 20/05/2019
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5. Reduction of electric arc furnace dust pellets by mixture containing hydrogen
Abstract The large amount of dust generated in electric arc furnace aligned with its chemical composition makes this dust a potential source of iron in the direct reduction iron process. Thus, the aim of this research is to investigate the reduction of pellets produced with electric arc furnace dust using hydrogen as the reducing agent. The kinetic investiga
REM, Int. Eng. J.. Publicado em: 2019-03
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6. Estudio de la actividad antifúngica de materiales conteniendo carbón proveniente de pilas en desuso
ABSTRACT The large number of batteries that are discarded and the environmental impact that the inadequate disposition of the waste of the same produces impelled to its recycling. Both alkaline and zinc-carbon batteries have as their main components zinc and carbon mixed with other oxides, in their internal fill. In this work, the silica synthesis was carrie
Matéria (Rio J.). Publicado em: 19/07/2018
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7. Characterization of Niobia-alumina Deposited by the Sol-gel Process on Carbon Steel
The precursor sols of Al2O3 and mixed NbxOy/Al2O3 oxides were synthesized by the sol-gel process using acetylacetone to control the reaction kinetics of the organometallic oxides in the mixture. The layers of the precursor sols of Al2O3 and NbxOy/Al2O3 were deposited on AISI steel 1020 by manual immersion (dip coating). The lyophilized sols were characterize
Mat. Res.. Publicado em: 16/04/2018
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8. The Effect of Electrolyte pH on the Ni-Co Mixed Oxides Coatings Produced from Citrate Baths
In this work, Ni-Co oxides coatings were produced using electrochemical techniques (chronopotentiometry and/or linear voltammetry) and solutions containing Ni2+ and Co2+ ions in the molar ratio 1: 2, sodium citrate as the ligand, and different pH values (7.5 and 10.5). Energy dispersive spectrometry (EDS), scanning electron microscopy (SEM), Raman spectrosco
Mat. Res.. Publicado em: 11/01/2018
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9. Lithium containing MgAl mixed oxides obtained from sol-gel hydrotalcite for transesterification
Abstract The innumerous advantages of heterogeneous catalysts employed in biodiesel production have stimulated the search for a solid catalyst capable of replacing the industrially used homogeneous catalysts. This paper investigates the effect of the sol-gel method in the catalytic activity and stability of Li-MgAl mixed oxides prepared by the “in situ”
Braz. J. Chem. Eng.. Publicado em: 2018-01
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10. Chemical and mineralogical characterization of silicon manganese iron slag as railway ballast
Abstract In nature, metal ores such as iron, lead, aluminum and others are found in an impure state, sometimes oxidized and mixed with silicates of other metals. During casting, when the ore is exposed to high temperatures, these impurities are separated from the molten metal and can be removed. The mass formed by these compounds is slag. Slag is the co-prod
REM, Int. Eng. J.. Publicado em: 2017-12
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11. New Multicomponent Reaction for the Direct Synthesis of β-Aryl-γ-nitroesters Promoted by Hydrotalcite-Derived Mixed Oxides as Heterogeneous Catalyst
A new approach based on multicomponent/domino combined reactions for the synthesis of γ-nitroesters promoted by a mixed aluminium-magnesium oxides derived from hydrotalcite-like material was developed. Different γ-nitroesters were synthesized in 15-95% yield using Meldrum's acid, aromatic aldehydes, nitromethane and different alcohols as reagents and solve
J. Braz. Chem. Soc.. Publicado em: 2017-02
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12. Gas-Phase Conversion of Glycerol to Acetol: Influence of Support Acidity on the Catalytic Stability and Copper Surface Properties on the Activity
Mesoporous mixed copper-aluminum oxides and copper-silicon oxides were synthesized with polymeric precursors route in order to evaluate the effect of the support acidity on the catalytic stability due to the carbon deposit and the copper surface characteristics on the catalytic activity for the gas-phase conversion of glycerol to acetol. The samples were cha
J. Braz. Chem. Soc.. Publicado em: 2016-12