Deactivation
Mostrando 1-12 de 453 artigos, teses e dissertações.
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1. Metal-Supported Niobium Catalysts Investigation for Conversion of Bio-Renewable Glycerol to Organic Compounds
The glycerol oxidative dehydration to organic compounds, especially acrolein and acrylic acid, was studied over vanadium, molybdenum, and cobalt oxides supported on niobium oxide and niobium phosphate catalysts. At 300 °C, the glycerol conversion was 100% over all catalysts tested, and acrolein was the main product observed, without significant deactivation
Journal of the Brazilian Chemical Society. Publicado em: 2022
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2. 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
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3. Obtaining geotechnical parameters from correlations between geophysics and CPT tests in tailings dams
Abstract This article introduces a hassle-free methodology for geotechnical parameters to be obtained from correlations between geophysics and CPT field tests in tailings dams undergoing the decommissioning process, which are reasonably representative of site conditions, from the very early project stages, with extensive coverage of all impoundment parts, wi
REM, Int. Eng. J.. Publicado em: 2020-12
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4. Regionalization of hydrological model parameters for the semi-arid region of the northeast Brazil
ABSTRACT This work deals with the regionalization of parameters of hydrological models in semi-arid regions with data scarcity, focusing on part of the Brazilian semi-arid region that involves the States of Ceará, Rio Grande do Norte, Paraíba and Pernambuco. The hydrological model adopted was the MODHAC - Self-Calibrating Hydrological Model. A total of 45
RBRH. Publicado em: 14/11/2019
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5. APPLICATION OF POLYCARBOXYLIC ACIDS AS BINDERS FOR TiO2 IMMOBILIZATION ON COTTON TEXTILES
ABSTRACT Immobilizing the photocatalyst on a support is an alternative solution to a critical issue in photocatalysis, which is the need for unit operations to remove the photocatalyst from the effluent. In this work, TiO2 was immobilized onto a cotton textile substrate by polycarboxylic acid binders (succinic and citric acids) using a solution deposition me
Braz. J. Chem. Eng.. Publicado em: 15/07/2019
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6. Performance evaluation of NiCo2O4 spinel as a catalyst for partial oxidation of methane
ABSTRACT The NiCo2O4 catalyst with spinel structure was prepared by a modified polymeric-precursor method using gelatin as an organic-directing agent. The obtained powder was characterized by XRD, TPR and tested on the partial oxidation of methane. The Rietveld analysis performed on the XRD pattern confirmed the crystallization of two phases, the spinel NiCo
Matéria (Rio J.). Publicado em: 20/05/2019
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7. Oxidative Dehydration of Glycerol over Molybdenum- and Vanadium-Based Catalysts
Surplus of glycerol production from the biodiesel industry has led to the search for glycerol conversion routes, the most common of which are dehydration and oxidative dehydration. Vanadium and molybdenum oxides were supported on γ-Al2O3 and their properties were analyzed through several characterization techniques, showing that the acidity increases after
J. Braz. Chem. Soc.. Publicado em: 08/04/2019
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8. Synthesis, Photophysical and Electrochemical Properties of Novel D-π-D and D-π-A Triphenylamino-Chalcones and β-Arylchalcones
A series of triphenylamino (TPA)-chalcones and triphenylamino-β-arylchalcones, displaying either D-π-D or D-π-A architecture, were synthesized through aldol condensations and Heck reactions. The chalcone derivatives display intense absorption bands ranging from 389 to 432 nm and molar extinction coefficients of ca. 105 L mol-1 cm-1 corresponding to π-π*
J. Braz. Chem. Soc.. Publicado em: 2019-01
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9. 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
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10. Resting spontaneous baroreflex sensitivity and cardiac autonomic control in anabolic androgenic steroid users
OBJECTIVES: Misuse of anabolic androgenic steroids in athletes is a strategy used to enhance strength and skeletal muscle hypertrophy. However, its abuse leads to an imbalance in muscle sympathetic nerve activity, increased vascular resistance, and increased blood pressure. However, the mechanisms underlying these alterations are still unknown. Therefore, w
Clinics. Publicado em: 21/05/2018
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11. 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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12. Electroremediation of deactivated catalysts from fluidised catalytic cracking for vanadium removal - the effect of a dual cathode chamber reactor
Abstract The aim of this study was to evaluate the quantity of vanadium removed through electrokinetic remediation applied to catalyst waste used in a fluid catalytic cracking process. In excess, vanadium affects process efficiency by reducing the catalyst’s activity, causing deactivation and reducing its useful life in petroleum cracking during refining.
Braz. J. Chem. Eng.. Publicado em: 2018-01