Active Alumina
Mostrando 1-12 de 32 artigos, teses e dissertações.
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1. REMOVAL OF NITRATE FROM DRINKING WATER BY USING PdCu STRUCTURED CATALYSTS BASED ON CORDIERITE MONOLITHS
Abstract Structured catalysts were prepared, characterized and evaluated in NO3 - removal from drinking water. Different suspensions containing a previously optimized PdCu/5wt% ZrO2-Al2O3 powder catalyst (hereinafter PdCu/5ZAp) were prepared and deposited on cordierite monoliths by washcoating. The effect of suspension concentration, the particle size, the i
Braz. J. Chem. Eng.. Publicado em: 30/09/2019
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2. 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
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3. NANOPARTICLES OF TUNGSTEN AS LOW-COST MONOMETALLIC CATALYST FOR SELECTIVE HYDROGENATION OF 3-HEXYNE
Low-cost tungsten monometallic catalysts containing variable amounts of metal (4.5, 7.1 and 8.5%W) were prepared by impregnating alumina with ammonium metatungstate as an inexpensive precursor. The catalysts were characterized using ICP, XPS, XRD, TPR and hydrogen chemisorption. These techniques revealed mainly WO3-Al2O3 (W6+) species on the surface. The eff
Quím. Nova. Publicado em: 2016-01
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4. Luminescent Terbium Doped Aluminate Particles: Properties and Surface Modification with Asparagine
New luminescent organic-inorganic hybrid particles based on Tb-doped aluminates and asparagine (Asn) surface modifiers were investigated. The Tb3+ doped inorganic core was obtained by spray pyrolysis, at 200 ºC γ-AlOOH (BOE:Tbx%) or at 700 ºC γ-Al2O3 (γTA:Tbx%). The reaction of Asn with boehmite in water disaggregated the sub-micronic boehmite particles
J. Braz. Chem. Soc.. Publicado em: 2015-12
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5. Experience on a Low Cost Way to Obtainal-Ti Ceramic Foams
An experience on a simple process for producing alumina-rutile-mullite ceramic foams by using aqueous particulate slurries is proposed. The sintering process is achieved in one unique thermal process at 1200 ºC in air. The description of the process, physical properties and morphological studies are reported. Microstructure is studied by using confocal opti
Mat. Res.. Publicado em: 2015-08
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6. CARACTERIZAÇÃO E ATIVIDADE CATALÍTICA DE K2CO3/AL2O3 NA TRANSESTERIFICAÇÃO DO ÓLEO DE GIRASSOL COM AQUECIMENTO CONVENCIONAL E MICRO-ONDAS
Commercial and synthetic mesoporous aluminas impregnated with potassium carbonate were characterized by X-ray diffraction (XRD), nitrogen physisorption, infrared spectroscopy and 27Al MAS NMR. The activities in the transesterification reaction of sunflower oil with methanol for biodiesel production were evaluated. 27Al MAS NMR spectra evidenced the presence
Quím. Nova. Publicado em: 2015-02
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7. Concretes with red mud coarse aggregates
Red mud (RM) is a mineral waste, residue of the Bayer process used to obtain alumina from bauxite. While the exploration of rolled pebble damages the environment and is much more controlled by the government, the huge RM disposal areas do not stop increasing and polluting soil, rivers and groundwater sources in Amazon. In this work, the material mixtures use
Materials Research. Publicado em: 27/03/2012
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8. Palladium-supported catalysts in methane combustion: comparison of alumina and zirconia supports
Palladium catalysts supported on alumina and zirconia were prepared by the impregnation method and calcined at 600 and 1000 ºC. Catalysts were characterized by BET measurements, XRD, XPS, O2-TPD and tested in methane combustion through temperature programmed surface reaction. Alumina supported catalysts were slightly more active than zirconia supported cata
Química Nova. Publicado em: 2012
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9. Experimental and theoretical research on catalytic synthesis of thiophene from furan and H2S
The yield of thiophene from furan and H2S was investigated using selected catalyst carriers (alumina, active carbon and silica gel) and active ingredients (silicotungstic, phosphomolybdic and phosphotungstic acids) to obtain the optimized synthesis parameters. The experimental results indicated that the yield of thiophene reached a maximum when the supported
Brazilian Journal of Chemical Engineering. Publicado em: 2011-03
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10. Caracterização de catalisadores usados na oleoquímica
In order to improve the physical-chemical properties of bio oil from castor oil were used as catalysts silica and alumina, both pure and doped. The study showed that products from the catalytic cracking of castor oil have properties more satisfactory, especially when using alumina. This fact can be explained by higher acidity, mesoporous characteristic and s
Publicado em: 2010
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11. DEVELOPMENT OF CERAMIC COMPOSITES FROM MIXTURE OF ALUMINA AND CERAMIC PRECURSOR POLYMER POLY (SILSESQUIOXANE) / Desenvolvimento de compósito cerâmico a partir de mistura de alumina e polímero pecursor cerâmico polissilsesquioxano
Processing of ceramics materials, by polymer precursors pyrolysis, has been intensively researched over the past decades, due to advantages that this path provides, such as: lower temperature process compared to conventional techniques; structure control at molecular level; synthesis possibility of a wide range of ceramic compounds; obtaining parts with dime
Publicado em: 2009
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12. Compósitos cerâmicos porosos de alumina - zircônia para aplicação em sistemas de controle térmico para satélites: obtenção e caracterização / Alumina-zirconia porous ceramic composites for application in satellite thermal control systems: obtaining and characterization
To control the temperature of satellites are used various thermal control heat systems. The Loop Heat pipe (LHP) are being developed at the DEM (Space Mechanic and Control Division) of the INPE (National Institute for Space Research) an apparatus for passive heat control of the satellites components. The main components of the LHP system are: capillary evapo
Publicado em: 2008