Transition Metal Catalysts
Mostrando 1-12 de 22 artigos, teses e dissertações.
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1. New Strategies in Enantioselective Hydrogenation on Supported Transition Metal Catalyst: Effects of Metal Sintering and Support Swelling
The effect of noble metal catalysts supported on an ionic exchange resin for the enantioselective hydrogenation of ethyl pyruvate to ethyl lactate was studied. High activity and moderate enantioselectivity levels were obtained. Pt was the best enantioselective metallic phase, followed by Pd and Au; Rh was the less enantioselective metallic phase. The effect
J. Braz. Chem. Soc.. Publicado em: 12/08/2019
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2. IRON OXIDE AND Fe2O3/Al2O3 USED TO CATALYZE REMOVING HYDROGEN FROM TAIL CHLORINE AT LOW TEMPERATURE
The transition metal oxide, such as iron oxide and Fe2O3/Al2O3 is cheap and industrialized that are widely used to catalyze the reaction of chlorine and oxygen with hydrogen in mixture gas to remove hydrogen from tail chlorine at low temperature. The reaction gas was prepared by the same composition with industrial tail chlorine, namely Cl2 (65% ~ 80%), O2 (
Quím. Nova. Publicado em: 02/05/2019
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3. ROMP como um método versátil para a obtenção de materiais poliméricos diferenciados
Ring Opening Metathesis Polymerization (ROMP) of cyclic olefins is a powerful transition metal-catalyzed reaction for syntheses of polymers and copolymers. The key feature of this reaction is the [2+2]-cycloaddition mechanism, with retention of the olefinic unsaturation in the polymer chain and occurrence of living polymerization. With the development of met
Química Nova. Publicado em: 2012
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4. Selective hydrogenation of 1,3-butadiene by transition metal compounds immobilized in 1-butyl-3-methyl imidazolium room temperature ionic liquids
Os complexos [Co(acac)2], [Co(acac)3], [Fe(acac)3] e [Ni(acac)2] (acac = acetilacetonato) dissolvidos em tetrafluoroborato de 1-butil-3-metilimidazônio (1), trifluorometanosulfonato de 1- butil-3-metilimidazólio (2) ou hexafluorofosfato de 1-butil-3-metilimidazólio (3), catalisam a hidrogenação de 1,3-butadieno em butenos em sistema catalítico tipicame
Publicado em: 2010
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5. Transition metal-based bimetallic catalysts for the chemoselective hydrogenation of furfuraldehyde
Neste trabalho foi estudada a hidrogenação quimiosseletiva em fase líquida do furfural, empregando-se catalisadores baseados em Pt, Rh e Ni. Sistemas bimetálicos, contendo diferentes quantidades de estanho, foram obtidos por meio de reações de superfície controlada entre um catalisador monometálico e Sn(C4H9)4. Quando foram utilizados catalisadores m
Journal of the Brazilian Chemical Society. Publicado em: 2010
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6. Selective hydrogenolysis of glycerol on ruthenium catalysts supported on niobium, silica and alumina / Hidrogenólise seletiva do glicerol em catalisadores de rutênio suportado em nióbio, sílica e alumina
Foram avaliados os catalisadores de Ru suportados em Nióbia, Sílica e Alumina na Hidrogenólise seletiva de Glicerol para a obtenção de propanodióis (1,2 e 1,3 - Propanodiol). O método de preparação utilizado para os três catalisadores foi o de impregnação úmida partindo-se de uma solução aquosa do sal precursor RuCl3.1,37H2O cuja porcentagem e
Publicado em: 2010
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7. Lanthanum based high surface area perovskite-type oxide and application in CO and propane combustion
The perovskite-type oxides using transition metals present a promising potential as catalysts in total oxidation reaction. The present work investigates the effect of synthesis by oxidant co-precipitation on the catalytic activity of perovskite-type oxides LaBO3 (B= Co, Ni, Mn) in total oxidation of propane and CO. The perovskite-type oxides were characteriz
Eclética Química. Publicado em: 2009
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8. Optimization of the biodiesel synthesis of physic nut (jatropha curcas L.), via ethanol route, and determination of its uid-dynamic parameters / Otimização da síntese etanólica do biodiesel de pinhão manso (Jatropha curcas L.) e determinação de seus parâmetros fluidodinâmicos
The most applied process for biodiesel production is the transesterification reaction based on alkaline catalysts, due to their faster kinetics and appreciable conversion rate. Then, low cost catalysts (alkaline, alkaline earth and transition metal hydroxides), are often used. In such context, the present work aims to evaluate the catalytic activity of alkal
Publicado em: 2009
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9. Catalisadores à base de Cu, Co ou Fe trocados ou suportados em zeólita USY avaliação na redução de NO com CO
The emissions of the nitrogen oxides (NOx) must be hardly reduced in the next years. The catalytic reduction of NO with CO is one of the possible processes with potential to be able to transform those oxides in N2. In that process, supported noble metals have been the most used, however, their low stability in the presence of water steam or SO2, have led to
Publicado em: 2008
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10. Estudo da oxidação total do etanol usando óxidos tipo perovskita LaBO3 (B= Mn, Ni, Fe)
The present work investigated the effect of coprecipitation-oxidant synthesis on the specific surface area of perovskite-type oxides LaBO3 (B= Mn, Ni, Fe) for total oxidation of ethanol. The perovskite-type oxides were characterized by X-ray diffraction, nitrogen adsorption (BET method), thermogravimetric analysis (TGA-DTA), TPR and X-ray photoelectron spect
Química Nova. Publicado em: 2007-10
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11. Early and post transition metal complexes as a single of combined components in the ethylene and isoprene polynerization
In this work is reported, in a first step, the effect of different experimental parameters and their relation with polymer properties using the homogeneous binary catalyst system composed by Ni(α-diimine)Cl2 (α-diimine = 1,4-bis(2,6-diisopropylphenyl)- acenaphthenediimine) and {TpMs*}V(Ntbu)Cl2 (TpMs* = hydridobis(3-mesitylpyrazol-1- yl)(5-mesitylpyrazol-1
Publicado em: 2007
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12. Síntese e caracterização de catalisadores de LaNiO3 não suportados e suportados em Al2O3 e ZrO2 para a reforma a vapor do metano
Ionic oxides with ABO3 structure, where A represents a rare earth element or an alkaline metal and B is a transition metal from group VIII of the periodic table are potential catalysts for oxidation and good candidates for steam reforming reaction. Different methods have been considered for the synthesis of the oxide materials with perovskite structure to pr
Publicado em: 2007