Chemisorption
Mostrando 1-12 de 46 artigos, teses e dissertações.
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1. CATALYTIC OXIDATION OF ISOPROPYL ALCOHOL OVER PLATINUM BASED CATALYST: A STUDY OF THE EFFECT OF METHYL CELLULOSE ON Pt PARTICLES DISPERSION OVER MULLITE
Abstract Isopropyl alcohol (IPA) catalytic oxidation remains one of the most popular techniques to remove volatile organic compounds from indoor places. In our study, catalytic oxidation of IPA was investigated on catalysts based on platinum deposited on mullite (Al6Si2O13), known for its excellent thermal stability. Pt/Al6Si2O13 catalysts were prepared by i
Braz. J. Chem. Eng.. Publicado em: 09/12/2019
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2. Adsorção de eteramina em caulinita natural e tratada com H2O2: proposição de alternativas para o tratamento de efluentes de mineração
RESUMO O presente trabalho consistiu em comparar a eficiência de adsorção de eteramina em caulinita natural (CN) e caulinita modificada com peróxido (CP). Com o intuito de otimizar o processo e avaliar a influência existente entre os parâmetros foi empregado a Metodologia de Superfície de Resposta com os sistemas adequados ao modelo quadrático associ
Matéria (Rio J.). Publicado em: 20/05/2019
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3. Chemical modification of in natura collagen by acidic catalysis – structural characterization and mechanistic features of Cd(II) sorption by solution microcalorimetry
ABSTRACT Chemically-modified in natura collage was prepared under acidic catalysis for using in sorption of Cd(II) from aqueous solutions. Simultaneous determination of the quantity and energetic parameters of Cd(II) sorption on PGA-scale at pH 8.0 were determined using solution microcalorimetry (SM). The calorimetric enthalpies of Cd(II) sorption on PGA-sca
Matéria (Rio J.). Publicado em: 06/12/2018
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4. HIDROGÉIS NANOCOMPÓSITOS DE POLISSACARÍDEO COM ZEÓLITA: AVALIAÇÃO DO PROCESSO DE ADSORÇÃO DO PESTICIDA PARAQUAT
In this work, nanocomposites formed from the natural polymer carboxymethylcellulose in combination with the polyacrylamide polymer and zeolite were obtained and characterized in relation to pesticide sorption capability. Hydrogels are three-dimensional network with large capacity of water or biological fluid adsorption. They have biocompatibility, biodegrada
Quím. Nova. Publicado em: 2018-04
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5. MORE ACTIVE AND SULFUR RESISTANT BIMETALLIC Pd-Ni CATALYSTS
The influence of the kind of metal precursor and the sequence of impregnation on the properties of Pd-Ni catalysts was evaluated during the test reaction of selective hydrogenation of styrene to ethylbenzene by means of physicochemical characterization. The focus was put on the final hydrogenating activity and the resistance to deactivation by sulfided compo
Quím. Nova. Publicado em: 2018-02
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6. 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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7. VAPOR-PHASE CATALYTIC CONVERSION OF ETHANOL INTO 1,3-BUTADIENE ON Cr-Ba/MCM-41 CATALYSTS
AbstractAl-MCM-41, 16%Ba/Al-MCM-41 and 1.4%Cr-16%Ba/Al-MCM-41 were used as catalysts in the vapor-phase catalytic conversion of ethanol. Physical-chemical properties of the catalysts and the effect of barium and chromium on the Al-MCM-41 activity and 1,3-butadiene yield were studied. The catalysts were characterized by X-ray diffraction (XRD), N2 physisorpti
Braz. J. Chem. Eng.. Publicado em: 2015-06
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8. Catalytic oxidation of volatile organic compounds (n-hexane, benzene, toluene, o-xylene) promoted by cobalt catalysts supported on γ-Al2O3-CeO2
Cobalt catalysts supported on γ-alumina, ceria and γ-alumina-ceria, with 10 or 20%wt of cobalt load, prepared by the wet impregnation method and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), field emission transmission electron microscopy (FETEM), N2 adsorption-desorption isotherms (BET/BJH methods), energy-dispersive X-ray
Braz. J. Chem. Eng.. Publicado em: 2014-09
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9. High performance maleated lignocellulose epicarp fibers for copper ion removal
Natural lignocellulosic fiber epicarp extracted from the babassu coconut (Orbignya speciosa) was chemically modified through reaction with molten maleic anhydride without solvent, with incorporation of 189.34 mg g-1 of carboxylic acid groups into the biopolymer structure. The success of this reaction was also confirmed by the presence of carboxylic acid band
Braz. J. Chem. Eng.. Publicado em: 2014-03
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10. Estudo de catalisadores de níquel suportados em cinza de casca de arroz na reforma de metano com dióxido de carbono visando a produção de hidrogênio e gás de síntese
Rice husk ash (RHA) is used as a silica source for several purposes, among them to obtain metal catalysts, as was done in this work. The catalysts were characterized by chemisorption, physisorption, thermal analyses (TG, DSC), X-ray diffraction, X-ray fluorescence, temperature-programmed reduction and scanning electron microscopy. The catalysts synthesized w
Quím. Nova. Publicado em: 2014
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11. Especiação e quimissorção de Pb(II) em rejeito de caulim
This study assesses the adsorption of Pb(II) on natural kaolin waste (KRnatural) and on that treated with 3 mol L-1 H2SO4 and HCl. Equilibrium and thermodynamic parameters were determined. The results indicate that the values of CEC, specific area and SiO2/Al2O3 ratio (4.6-6.0 cmol kg-1, 14.0-16.0 m² g-1 and 1.16-1.30, respectively) vary only slightly for t
Quím. Nova. Publicado em: 2013
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12. Uso de silicatos modificados na remoção de corantes de efluentes aquosos
This thesis describes the preparation, characterization and application of new inorganic/organic hybrid materials, obtained from organo-functionalization of lamellar surface of derivatives of keniaíta, magadeíta and RUB-18 silicates. The products obtained were treated with silylating agents by different methods. The materials were characterized by FTIR for
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 2012