Catalytic Hydrogenation
Mostrando 1-12 de 62 artigos, teses e dissertações.
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1. Theoretical Calculations on the Mechanism of Hydrogenation of Diphenylacetylene over Pdn (n = 1-4) Clusters
Diphenylacetylene (DPA) is a precursor of stilbene and benzil, and reduction of DPA or its derivatives with metallic reagents is both an old and contemporary topic of research. By means of density function theory (DFT) calculations, a detailed investigation of the mechanism of the hydrogenation of DPA over Pd clusters was carried out at the molecular level.
J. Braz. Chem. Soc.. Publicado em: 2020-10
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2. Influence of the Capping Agent PVP of the Outer Layer of Pd Nanocubes Surface on the Catalytic Hydrogenation of Unsaturated C−C Bonds
The excess of capping agents used during the synthesis of nanoparticles is usually removed by solvent washing. The influence of the amount of polyvinylpyrrolidone (PVP) capping agent in the catalytic activity of palladium nanocubes was evaluated, after different numbers of washing cycles in the purification step performed after the syntheses of the nanoparti
J. Braz. Chem. Soc.. Publicado em: 2020-05
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3. Gold Catalysis for Selective Hydrogenation of Aldehydes and Valorization of Bio-Based Chemical Building Blocks
Gold catalysts are best known for their selectivity in oxidation reactions, however, there is a promising future for gold in selective hydrogenations. Herein, the hydrogenation of several aldehydes and important bio-based chemical building blocks, namely 5-hydroxymethylfurfural (5-HMF), furfural and vanillin, was performed throughout the combination of Au na
J. Braz. Chem. Soc.. Publicado em: 21/10/2019
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4. NOVOS HÍBRIDOS BASEADOS EM OXIHIDRÓXIDO DE FERRO(III) E NANOPARTÍCULAS DE OURO (AuNPs/FeOOH) COMO CATALISADORES PARA A REDUÇÃO DE POLUENTES ORGÂNICOS AMBIENTAIS
A new δ-FeOOH supported nano-Au catalyst was prepared by a facile method using HAuCl4 as the gold source and NaBH4 as the reducing agent. The samples (denoted as AuNPs/FeOOH) were characterized by means of X-ray diffraction (XRD), UV-vis and infrared spectroscopies and scanning electron microscope (SEM). The obtained characterization data confirmed the form
Quím. Nova. Publicado em: 2017-06
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5. MODELING STYRENE HYDROGENATION KINETICS USING PALLADIUM CATALYSTS
Abstract The high octane number of pyrolysis gasoline (PYGAS) explains its insertion in the gasoline pool. However, its use is troublesome due to the presence of gum-forming chemicals which, in turn, can be removed via hydrogenation. The use of Langmuir-Hinshelwood kinetic models was evaluated for hydrogenation of styrene, a typical gum monomer, using Pd/9%N
Braz. J. Chem. Eng.. Publicado em: 2016-09
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6. ADVANCED CONTROL OF A COMPLEX CHEMICAL PROCESS
Abstract Three phase catalytic hydrogenation reactors are important reactors with complex behavior due to the interaction among gas, solid and liquid phases with the kinetic, mass and heat transfer mechanisms. A nonlinear distributed parameter model was developed based on mass and energy conservation principles. It consists of balance equations for the gas a
Braz. J. Chem. Eng.. Publicado em: 2016-03
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7. Iridium Oxidation States in Catalytic Hydrogenation Intermediates
Os conhecidos hidretos de irídio(III) [IrH2(NCMe)3(PiPr3)]BF4, [IrH(h3-C3H5)(NCMe)2(PiPr3)]BF4, [IrH(E-CH=CHPh)(NCMe)3(PiPr3)]BF4 e [IrH{C(Ph)=CH2}(NCMe)3(PiPr3)]BF4, derivados do precursor catalítico tipo Crabtree [Ir(cod)(NCMe)(PiPr3)]BF4, foram investigados em reações com substratos tipicamente envolvidos na catálise homogênea de hidrogenação. Nov
J. Braz. Chem. Soc.. Publicado em: 2014-12
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8. Metal nanoparticles/ionic liquid/cellulose: polymeric membrane for hydrogenation reactions
Rhodium and platinum nanoparticles were supported in polymeric membranes with 10, 20 and 40 µm thickness. The polymeric membranes were prepared combining cellulose acetate and the ionic liquid (IL) 1-n-butyl-3-methylimidazolium bis(trifluoromethane sulfonyl)imide (BMI.(NTf)2. The presence of metal nanoparticles induced an increase in the polymeric membrane
Polímeros. Publicado em: 18/04/2014
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9. Modelagem do escoamento em reator catalítico de membrana cerâmica para hidrogenação parcial trifásica. / Modeling flow in ceramic catalytic membrane reactor for partial three-phase hydrogenation.
No presente trabalho, foi desenvolvido um modelo para o escoamento em reator de membrana do tipo contator ativo, através da abordagem de dinâmica dos fluidos computacional (CFD), utilizando o código comercial ANSYS FLUENT. O modelo incluiu todo o módulo de membrana constituído por uma membrana tubular e um casco metálico. A reação modelo estudada foi
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 25/11/2011
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10. Busca heurística e inferência de parâmetros cinéticos de reações de hidrotratamento de óleo diesel a partir de dados experimentais escassos
Currently, the amount of contaminants (such as sulfur, nitrogen and aromatics) in diesel oil is strictly controlled, due to their impact on pollutant emissions. The most important process used to meet fuel specifications regarding contaminants is the catalytic hydrogenation, specifically hydrotreatment (HDT). Optimization of the HDT process can benefit from
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 30/06/2011
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11. Síntese e atividade antifúngica do avenaciolídeo e de bis-γ-lactonas análogas com cadeias laterais alifáticas / Synthesis and antifungal activity of avenaciolide and bis-γ-lactonas with alifhatic lateral chains
Avenaciolide is a natural product with an α,β-unsaturated bis-γ-lactone structure and a linear lateral chain with eight carbon atoms. Using the Chiral pool strategy, two avenaciolide analogs were prepared from D-glucose, containing linear lateral chains of 11 and 17 carbon atoms, [A] and [B], respectively. The different lateral chains were add
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 25/02/2010
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12. Liquid phase hydrogenation of acethydrazone to N'-methyl acethydrazide over Pd/γ-Al2O3 catalyst
Catalytic hydrogenation of acethydrazide (AH) is the main step in the production of N'-methyl acethydrazide (MAH). In this step, AH reacts with formaldehyde to produce acetylhydrazone (AOH). AOH is hydrogenated in the presence of 5% Pd/γ-Al2O3 catalyst to MAH. In this paper, the effects of hydrogen pressure, catalyst loading and initial concentration of AOH
Brazilian Journal of Chemical Engineering. Publicado em: 2010-03