Oxides
Mostrando 1-12 de 722 artigos, teses e dissertações.
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1. Bimetallic Au-Pd/α-MoO3 Catalyst with High Oxygen Vacancies for Selective Oxidation of Cinnamyl Alcohol
Supported Au-Pd nanoparticles (NPs) have been extensively studied in alcohol oxidation reactions. However, few studies use reducible metal oxides as support, which can activate oxygen molecules and boost the selectivity of the reaction. In this work, Au-Pd NPs were supported on α-MoO3 and evaluated in the selective oxidation of cinnamyl alcohol without solv
Journal of the Brazilian Chemical Society. Publicado em: 2023
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2. The influence of compositional variability of dimension stone residues on the properties of rustic porous ceramic tiles
Abstract This study analyzed how the compositional variability of dimension stone residues influences the characteristics of rustic porous ceramic tiles. The specimens were prepared by adding 20 wt% of dimension stone residue to the clay and sintered at 1000 °C for 1 h. The testing assays performed were physical properties and structural analysis through sc
Cerâmica. Publicado em: 2023
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3. Nitrogen Oxides Levels in the Atmosphere of Different Brazilian Urban Centers, by Passive Sampling
Urban air pollution is still an emerging environmental problem, it causes damage to health and is difficult to be controlled in urban centers. The population of large metropolises is often exposed to concentrations of nitrogen oxides (NOx), mainly due to vehicle emissions. Epidemiological studies claim that exposure to these oxides is strongly correlated wit
Journal of the Brazilian Chemical Society. Publicado em: 2022
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4. 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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5. Metal-Supported Niobium Catalysts Investigation for Conversion of Bio-Renewable Glycerol to Organic Compounds
The glycerol oxidative dehydration to organic compounds, especially acrolein and acrylic acid, was studied over vanadium, molybdenum, and cobalt oxides supported on niobium oxide and niobium phosphate catalysts. At 300 °C, the glycerol conversion was 100% over all catalysts tested, and acrolein was the main product observed, without significant deactivation
Journal of the Brazilian Chemical Society. Publicado em: 2022
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6. Heterogeneous Fenton-like catalytic degradation of phenazine dye over CeO2 (CP-2) nanoscale powder
Abstract A heterogeneous Fenton-like process was explored for oxidation of phenazine dye using ceria polishing material (CP-2). XRD, SEM, FTIR, UV-vis DRS, and pHPZC techniques were applied to characterize the catalyst features. The performance of the heterogeneous Fenton-like process was investigated under various parameters (reaction time, pH, H2O2 concent
Cerâmica. Publicado em: 2022
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7. Perovskite-Type Oxides La0.6M0.4Ni0.6Cu0.4O3 (M = Ag, Ba, Ce) towards the Oxygen Reduction Reaction (ORR) in Alkaline Medium: Structural Aspects and Electrocatalytic Activity
In this work, La0.6M0.4Ni0.6Cu0.4O3 (M = Ag, Ba, and Ce, denoted as LANC, LBNC, and LCNC, respectively) electrocatalysts were synthesized by the Pechini method at 1023 K for two hours in air. Rietveld refinement allowed the identification of the crystallographic phases present in all oxides. The electrocatalytic performance of these oxides towards the oxygen
J. Braz. Chem. Soc.. Publicado em: 2021-03
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8. Influence of Mn2+ ions on depression of quartz and spessartine in gondite ore
Abstract Low-grade manganese ores that are composed of manganese oxides, wad, quartz, iron oxides, gibbsite, and especially of spessartine (Mn3Al2(SiO4)3) are known as gondite. Spessartine is a mineral with a high content of silica (SiO2) and alumina (Al2O3) that causes a decrease of the enrichment in manganese oxide concentrates by flotation, giving this o
REM, Int. Eng. J.. Publicado em: 2021-01
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9. Application of Nickel Ferrite Nanoparticles in Adsorption of Amoxicillin Antibiotic
According to the World Health Organization, amoxicillin (AMX) is the most widely consumed antibiotic in the world. Consequently, there is great interest in the development of new technologies that allow the removal of this type of contaminant, as exposure to antibiotic residues can cause a variety of adverse effects, such as toxicity and antimicrobial resist
J. Braz. Chem. Soc.. Publicado em: 2020-12
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10. Influence of synthetic slag added during the tapping on inclusion features of a vacuum degassed LCAK steel grade
Abstract Synthetic slag has been added during BOF tapping in order to modify the physicochemical properties of resulting slag with the aim of assessing the influence on inclusion density, composition and size distribution. Viscosities and activities of slag oxides were calculated by FactSage 7.2, using the FToxid database and Viscosity module. All heats were
REM, Int. Eng. J.. Publicado em: 2020-12
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11. Design, Synthesis, and Application of Colored Cobalt Pigments (Pink, Blue, Green)
The combination of white or colorless oxides (MgO, Al2O3, ZnO) with colorant ions (Co2+) generates colored pigments (pink, blue, green). The color is caused by the insertion of the colorant ion in the respective crystal lattices (periclase, alumina, wurtzite), as verified by X-ray diffraction. Absorption spectra in the visible region show analogous triplet b
J. Braz. Chem. Soc.. Publicado em: 2020-11
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12. Analysis of cracks and coating in iron ore pellets by digital image processing
Abstract The pelletizing process agglomerates ore fines previously considered as tailings and makes its application possible in the form of pellets. During the process, the pellets are subjected to various compressive forces and temperature changes, which cause ruptures in their surface. These ruptures (cracks) impair the performance of the pellets in the re
REM, Int. Eng. J.. Publicado em: 2020-09