Catalysis
Mostrando 13-24 de 1422 artigos, teses e dissertações.
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13. OXIDATIVE STABILITY AND COLD FILTER PLUGGING POINT OF BIODIESEL BLENDS DERIVED FROM FATS AND SOY OIL
Biodiesel made from oils is rich in polyunsaturated fatty acids methyl esters, and, consequently, presents high tendency to oxidize. Biodiesel made from fats, on the other hand, is mainly comprised by saturated chains. Although it is highly stable, they easily crystalize at low temperatures. Blends from both can exhibit optimized properties. In this work, ox
Quím. Nova. Publicado em: 2020-09
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14. A New Energetic Complex: Synthesis, Structure, and Combustion Catalysis Performance
The potential of tetrazole-based ligands for forming energetic complexes applied in pyrotechnics and propellants is demonstrated with the use of 5,5’-(1,3-phenylene)bis(1H-tetrazole) (H2BTB) to generate an energetic complex with high energy. A new energetic complex of PbII-tetrazolate, [Pb2(BTB)2(H2O)8]·5H2O (1), was synthesized and structurally character
J. Braz. Chem. Soc.. Publicado em: 2020-08
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15. SYNERGISMS BETWEEN METAL AND PHOTOREDOX CATALYSIS: DECONVOLUTING COMPLEX SYSTEMS
This review briefly describes the evolution of organometallic chemistry and photoredox catalysis as independent fields; followed by a more in-depth presentation and discussion of representative examples derived from their synergistic combination, which generally leads to powerful cross-coupling protocols. In this context, the rational deconvolution of these
Quím. Nova. Publicado em: 20/07/2020
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16. Investigating Surface Properties and Lithium Diffusion in Brookite-TiO2
Surfaces properties of TiO2 in the brookite phase and the lithium diffusion are studied using density functional theory (DFT) and interatomic potential simulations. Simulations predict that the brookite surfaces have a higher intrinsic Lewis acidity compared to the other polymorphs due to the presence of four coordinated Ti atoms on the surface in contrast t
J. Braz. Chem. Soc.. Publicado em: 2020-01
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17. Acid-Catalyzed Z-E Isomerization of γ-Alkylidenebutenolides: An Experimental and DFT Study
The Z-E isomerization of γ-alkylidenebutenolide analogues to natural nostoclides and other natural butenolides was investigated using 1H nuclear magnetic resonance (NMR) and high performance liquid chromatography (HPLC) data as well as density functional theory (DFT) calculations at the wB97x-D/6-31G(d,p) level, including solvent effects with the polarizabl
J. Braz. Chem. Soc.. Publicado em: 2020-01
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18. Serpentinites: Mineral Structure, Properties and Technological Applications
Serpentine is a versatile mineral family rich in Mg silicate with several polymorphic phases, mainly antigorite and lizardite, all of them with similar chemical composition (Mg3Si2O5(OH)4). Their structures are generally composed of octahedral layers rich in Mg[MgO2(OH)4]6- , attached to a tetrahedral silicate [Si2O5]2- sheet. The unique physicochemical prop
J. Braz. Chem. Soc.. Publicado em: 2020-01
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19. LIPASE - CATALYZED FORMATION OF PENTYL NONANOATE USING SCREENED IMMOBILIZED LIPASE FROM Rhizomucor meihei
Abstract Bio-catalysis has attracted the special attention of industrial flavour producers in the production of valuable ester compounds. In this study, the synthesis of pentyl nonanoate ester (a short chain ester with fruity aroma) was carried out with a commercial immobilized lipase from Rhizomucor meihei Lipozyme (RMIM) as biocatalyst in the esterificatio
Braz. J. Chem. Eng.. Publicado em: 09/12/2019
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20. Proteins and Peptides at the Interfaces of Nanostructures
Abstract: The present review focuses on the proteins and peptides at the interfaces of nanostructured metals and semiconductors as a result of their use in synthesis in-situ and functionalization of nanostructures. We start the review with an introduction about the peculiar properties of nanostructured materials and their applications. In the following, the
An. Acad. Bras. Ciênc.. Publicado em: 25/11/2019
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21. Synthesis and characterization of mesoporous materials with SBA and MCM structure types
Resumo Materiais mesoporosos são estruturas promissoras para aplicação em catálise e adsorção devido à elevada área superficial e grande tamanho dos poros. Materiais mesoporosos foram sintetizados pelo método hidrotérmico com novos surfactantes, distintos daqueles observados na literatura, a fim de realizar um estudo de sua estrutura e obter materi
Cerâmica. Publicado em: 14/11/2019
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22. On-Flow Ligand Screening Assay Based on Immobilized Nucleoside Diphosphate Kinase B from Homo sapiens
We describe an on-flow zonal affinity-based chromatography assay to screen ligands for the nucleoside diphosphate kinase B enzyme (NME2) from Homo sapiens. For the first time, we have covalently immobilized NME2 on the surface of an open fused silica capillary reactor (NME2-ICER) and placed the reactor before the analytical column, which resulted in a two-di
J. Braz. Chem. Soc.. Publicado em: 24/10/2019
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23. Catalytic Transformation Conditions of Ethanol on Dealuminated BEA Zeolites
Catalysis is an important tool in obtaining a range of derivative products from renewable sources, such as ethanol. Solid-state dealumination using ammonium hexafluorosilicate on the BEA zeolite under the treatment at temperature of 190 °C, 70 mol% dealumination in the presence of humidity and washing with buffer solution at 25 °C generated larger pores. T
J. Braz. Chem. Soc.. Publicado em: 21/10/2019
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24. 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