Heterogeneous Catalysis
Mostrando 37-48 de 60 artigos, teses e dissertações.
-
37. Obtenção de ésteres etílicos e metílicos, por reações de transesterificação, a partir do óleo da palmeira Latino Americana macaúba - Acrocomia aculeata / Isolation of methilic and ethilic esters, by transferification reactions, from macauba trees oils- , Acrocomia aculeata
Ethyl esters and methyl esters (biodiesel) from oils of the fruits of the palm tree macauba (Acrocomia aculeata) were obtained by transesterification reactions performing the alcoholysis (methanolysis and ethanolysis) under homogeneous basic catalysis (using KOH, NaOH, CH3CH2OK, CH3CH2ONa CH3OK and CH3ONa), under homogeneous acid catalysis (using HCl and H2S
Publicado em: 2007
-
38. Efecto de la naturaleza del precursor sobre las caracteristicas de las nanoparticulas de SnO2 sintetizadas
Tin oxide (SnO2) is widely used in industry as raw material for electronic devices, plating of different types of materials, for dyes and pigments, for electroplating, heterogeneous catalysis, etc. In this work SnO2 was obtained by a controlled precipitation method with special attention to the effects the tin precursor has on the microstructure of the final
Química Nova. Publicado em: 2007
-
39. Preparação e caracterização de materiais com base zeolítica para aplicação em catálise
Today, heterogeneous catalysts are commonly used in chemical industries and became very important to several commercial processes. A key problem in catalysis is the evaluation of acid parameters in solid acids and their correlation with catalytic activity. This work involves the study of acidity for zeolites and heteropolyacids and their activity in model re
Publicado em: 2007
-
40. Preparação, caracterização e aplicação de H3PW12O40 suportado em zircônia
12-tungstophosphoric acid (H3PW12O40 or HPW) is a heteropolyacid largely used for homogeneous and heterogeneous catalysis. In this work, HPW was supported on zirconia (ZrO2) by impregnation in acidic (HCl 0.1 mol/L) aqueous solution at different ratios (5, 10, 15, 20, 25, 40 and 60 mass %). The solids were characterized by FTIR, XRD, FT-Raman, and 31P MAS-NM
Publicado em: 2007
-
41. Sintese e heterogeneização de complexos de paladio : aplicação em reações de acoplamento C-C / Synthesis and heterogeneization of palladium complexes : application in C-C cross-coupling reactions
In this work, palladium complexes, in which phosphored ligands are anchored to cyclophosphazenes were synthesized. These complexes, in solution or immobilized in inorganic matrices, were tested in the Suzuki cross-coupling reaction (between phenylboronic acid and bromobenzene, for example), the Stille cross-coupling reaction (between tributylvinyltin and
Publicado em: 2007
-
42. Adaptação de forno de microondas doméstico para realização de reações de transesterificação sob refluxo e catálise por argilas
The microwave oven became an important source of heating for many laboratory procedures including accelerating organic reactions. Reactions that require long reflux times can sometimes be carried out in a few hours or minutes in a conventional microwave oven. However, longer reflux times can be troublesome since domestic microwave ovens are not prepared for
Química Nova. Publicado em: 2006-04
-
43. Síntese e Caracterização de Peneiras Moleculares Microcoposas Tipo SAPO-34 e MeAPSO-34 / Synthesis and Characterization of microporous molecular sieves SAPO-34 and MeAPSO-34
Samples of SAPO-34 and MeAPSO-34 were prepared by two different procedures taken from literature, with small modifications. For MeAPSO-34 synthesis (Me/Al = 0,025 e 0,0075) Ni, Mn, Fe and Co nitrate were used. The NiAPSO-34 were obtained in two different Ni concentration (Ni/Al ratio of 0,025 and 0,0075). The synthesized samples were characterized by X-ray d
Publicado em: 2006
-
44. Construção e estudos de perfomance de um reator fotoquímico tipo CPC ("Compound Parabolic Concentrator")
A CPC (Compound Parabolic Concentrator) reactor was projected and constructed aiming to promote the degradation of the organic matter present in considerable volumes of aqueous effluents, under the action of solar radiation. The essays were done using a model effluent which consists of a mixture of fragments of a sodium salt of lignosulphonic acid possessing
Química Nova. Publicado em: 2005-10
-
45. Produção de etilenoglicóis e derivados por reações catalíticas do óxido de eteno
Products resulting from the ethoxylation of hydroxylated compounds, especially water and ethanol, are of great commercial importance. This work presents several aspects concerning the catalytic reactions of ethylene oxide, a chemical substance used in the production of a wide variety of products. Mechanisms of ethoxylation, distribution of products, formatio
Química Nova. Publicado em: 2005-03
-
46. Preparação e caracterização de hidrotalcitas Mg/AL calcinadas e suas propriedades cataliticas para reações de conversão de etanol / Preparation and characterization of calcined Mg/AL-Hydrotalcite and ethanol catalytic properties
Materiais do tipo hidrotalcita foram sintetizados, calcinados e caracterizados, assim como utilizados na conversão catalítica de etanol. As sínteses foram realizadas com razões molares AI/(AI + Mg) iguais a 0,20; 0,25 e 0,33; em todos os casos os difratogramas de raios-X demonstraram que, efetivamente, fases de hidrotalcitas tinham sido obtidas. Esses ma
Publicado em: 2005
-
47. Estudo de Agentes Alquilantes para o Cardanol Hidrogenado / Study of Alkylants Agents for the Hydrogenated Cardanol
This work has investigated the hydrogenated cardanol (3-PDP) alkylationâs process through the use of the following alkylating agents: methyl terc-butyl ether, cyclehexanol, isoamilic alcohol and glycerol. The alkylation process using alcohol was accomplished with the use of zinc chloride as catalyst in the range of temperature of 70 to 120 ÂC. The reaction
Publicado em: 2005
-
48. Síntese e modificação superficial do TiO2 visando aumentar a eficiência do processo de fotocatálise heterogênea no tratamento de compostos fenólicos / Synthesis and superficial modification of TiO2 aiming to improve the efficiency of heterogeneous photocatalysis process on phenolic compounds treatment
Este trabalho de mestrado descreve a avaliação do emprego do TiO2, obtido por diferentes rotas de sínteses e do TiO2 P25 ambos modificados superficialmente com prata e cobre, como catalisador no processo de fotocátalise heterogênea visando a degradação de fenol e efluentes industriais, especificamente efluentes fenólicos. A deterioração dos recurso
Publicado em: 2005