Thermal Deactivation
Mostrando 1-12 de 24 artigos, teses e dissertações.
-
1. ANODES FOR SOFC: REVIEW OF MATERIAL SELECTION, INTERFACE AND ELECTROCHEMICAL PHENOMENA
This paper presents a comprehensive interface and electrochemical phenomena review of different anodes for SOFC. In this way, it was possible to select some mixed electronic and ionic conductor materials alternatives to the conventional anode, Ni-YSZ conductor. New materials must present a satisfactory electronic and ionic conductivity at intermediate temper
Quím. Nova. Publicado em: 2021-01
-
2. LEWIS ACID SITES OF Mg2+-MODIFIED POLYSTYRENE SULFONIC ACID RESIN CATALYSYS FOR SYNTHESIS OF DIBUTYL SUCCINATE
The polystyrene sulfonic acid resin catalysts were fabricated, containing elements of Cl and Mg through oxidization and impregnation, and they were characterized by EDS, FT-IR spectra, Py-IR spectra, UV spectra, XPS and TGA to investigate their physiochemical properties. The catalytic performances of these catalysts were examined in the esterification reacti
Quím. Nova. Publicado em: 2018-06
-
3. 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
-
4. Biochemical studies on immobilized fungal β-glucosidase
β-Glucosidase from Aspergillus niger was immobilized on sponge by covalent binding through a spacer group (glutaraldehyde). Sponge-immobilized enzyme had the highest immobilization yield (95.67%) and retained 63.66% of the original activity exhibited by the free enzyme. The optimum pH of the immobilized enzyme remains almost the same as for the free enzyme
Braz. J. Chem. Eng.. Publicado em: 2013-12
-
5. Síntese e estudo da atividade eletrocatalítica de óxidos de metais de transição e de nanopartículas de prata e ouro para a reação de redução de oxigênio / Synthesis and study of the electrocatalytic activity of transition metal oxides, and silver and gold nanoparticles for the oxygen reduction reaction
The oxygen reduction reaction (ORR) was studied on electrocatalysts composed by pure and mixed transition metal oxides of Mn, Co, and Ni, including spinel-like structures, and by Ag, Au, and Ag3M/C (M= Au, Pt, Pd e Cu) bimetallic nanoparticles, in alkaline electrolyte. The transition metal oxides were synthesized by thermal decomposition of their nitrates, a
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 10/08/2011
-
6. DESENVOLVIMENTO DE CATALISADORES A BASE DE NÍQUEL COM ESTRUTURA PEROVSQUITA PARA A UTILIZAÇÃO NA PRODUÇÃO DE GÁS DE SÍNTESE.
Nickel-based catalysts with perovskite like structure have shown promising application in several catalytic reactions such as in the partial oxidation of methane to obtain syngas (H2 + CO). However, these properties are potentially influenced by synthesis methods, calcinations conditions (temperature, time and atmosphere) and substitutions of sites A and/or
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 28/03/2011
-
7. Thermal stability of the immobilized fructosyltransferase from Rhodotorula sp
The thermal stability of the extracellular fructosyltransferase (FTase) from Rhodotorula sp., recovered from cultivation medium by ethanol precipitation and immobilized onto niobium ore, was studied by Arrhenius plot, half - life profile, half - inactivation temperature (T50) and thermodynamic parameters. The Arrhenius plot showed two different behaviors wit
Brazilian Journal of Chemical Engineering. Publicado em: 2011-09
-
8. Estudo da desativação térmica de catalisadores à base de óxidos mistos de cério e zircônio / Study of thermal deactivation of catalysts based on mixed oxides of cerium and zirconium
Em termos ambientais, os catalisadores automotivos se destacam pelos resultados altamente significativos alcançados após seu uso obrigatório em veículos leves. No entanto, as condições térmicas em que eles operam podem levar a um processo de perda de atividade significativa, após certo tempo de operação. Dentro desse contexto, este trabalho estudou
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 07/08/2009
-
9. Catalisadores de Pt suportados, obtidos pelo método solgel : efeito do cério na atividade e estabilidade nas reações de reforma do metano
The effect of Ce as a structural and electronic promoter on the activity and stability of Pt catalysts supported on Al2O3 for methane reforming reactions were investigated to elucidate the metal-support interaction. Pt/Al2O3 and Pt/CeO2-Al2O3 catalysts were prepared by conventional method of wet impregnation on commercial supports and on CeO2- Al2O3 mixed ox
Publicado em: 2009
-
10. Immobilisation of Bacillus subtilis NRC33a levansucrase and some studies on its properties
Bacillus subtilis NRC33a levansucrase was immobilised on different carriers using different immobilisation methods including physical adsorption, covalent binding, ionic binding and entrapment. The immobilised enzyme prepared by covalent binding on chitosan through 3% gluteraldehyde had the highest immobilization yield (81.51%). Therefore, it was used as a t
Brazilian Journal of Chemical Engineering. Publicado em: 2008-06
-
11. Produção de açúcar invertido pelo uso de invertase imobilizada em resinas
This work aims to offer a contribution for the development of the production of invert sugar by invertase immobilized on ion exchanging resins. The experiments were conduced in a batch stirred microreactor with temperature control and magnetic agitation. Firstly, kinetic assays on free invertase were conduced aiming to determine the hydrolysis kinetic and th
Publicado em: 2007
-
12. Estudo da regeneração de aditivos para catalisadores de craqueamento aluminofosfatos (ALPOs)e silicoaluminofosfatos (SAPOs)
Heterogeneous catalysts such as aluminophosphate and silicoaluminophosphate, molecular sieves with AEL of ALPO-11 and SAPO-11, were synthesized by the hydrothermal method with the following molar composition: 2.9 Al +3.2 P + 3.5 DIPA +32.5 H20 (ALPO-11); 2.9 Al +3.2 P + 0.5 Si + 3.5 DIPA +32.5 H20 (SAPO-11) starting from silica (only in the SAPO-11), pseudob
Publicado em: 2007