Hydrotalcite
Mostrando 13-24 de 32 artigos, teses e dissertações.
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13. Síntese, Caracterização e Avaliação do Grau de Cristalinidade de Compostos Tipo Hidrotalcita
Os hidróxidos duplos lamelares (HDL) são também conhecidos como argilas aniônicas, devido à possibilidade de intercalação de espécies aniônicas no espaço interlamelar. Essa nomenclatura se refere às características estruturais, onde se destaca a presença de dois tipos de cátions metálicos na lamela destes compostos. Encontra-se, na literatura,
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 28/02/2011
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14. Produção de monoéster via etanólise por hidrotalcitas termoativadas : síntese e caracterização
Among biofuels of the 1st generation, biodiesel stands out for its equivalent features to those of mineral diesel, however less polluting. It can be obtained by transesterification of triglyceride fats or vegetable oils by (m)ethanolysis. Aiming at improving the chemical process, different types of catalysis have been studied: i) homogeneous (acid e.g. H2SO4
Publicado em: 2011
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15. Adsorção de arsênio(V) pelo compósito magnético hidrotalcita: óxido de ferro
In this work, hydrotalcite, a layered double hydroxide, had its adsorption and ion exchange properties combined with the magnetic properties of iron oxide to produce a magnetic adsorbent, HT-Fe. The removal of As(V) by a HT-Fe adsorbent was evaluated under various conditions. The Kinetic process was well described by a pseudo-second order rate model. The max
Química Nova. Publicado em: 2011
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16. Efeito da composição das correntes do conversor das unidades de FCC no desempenho catalítico de aditivos DESOx
Hydrotalcite-like compounds having Mg partially replaced by Cu or Mn were prepared and used as precursors for two mixed oxides (Cu-OM50 and Mn-OM50) that were evaluated for SOx removal in the presence of O2, NO and CO. Under SO2/O2 reaction system, SOx removal was slightly higher over Cu-OM50. The addition of CO and NO to the feed markedly hindered the SO2 o
Química Nova. Publicado em: 2009
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17. Síntese, caracterização e avaliação catalítica de Vo x/Mg yAlo x na reação de decomposição do isopropanol
Vanadium oxide supported on hydrotalcite-type precursors was studied in the decomposition of isopropanol. Hydrotalcite-type compounds with different y = Mg+2/Al+3 ratios were synthesized by the method of coprecipitating nitrates of Mg+2 and Al+3 cations with K2CO3 as precipitant. The X-ray diffraction patterns of Al-rich hydrotalcite precursors showed the pr
Química Nova. Publicado em: 2008
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18. Estudo de metalofármacos antiinflamatórios de cobre e dos materiais híbridos resultantes de suas imobilizações no hidróxido duplo lamelar hidrotalcita: síntese, caracterização e avaliação da atividade farmacológica / Studies of Anti-inflammatory Copper-based Drugs and Corresponding Hybrid Materials from their Immobilization on the Layered Double Hydroxide Hydrotalcite: Synthesis, Characterization and Evaluation of Pharmacological Activities
Non-steroidal anti-inflammatory drugs are widely consumed to treat inflammatory diseases and pain but their clinical use are limited due to serious side-effects on the gastrointestinal tract. The bioactivity of metal complexes exhibits great interest in metal-based drug research. Cu(II)-NSAID compounds show good anti-inflammatory property and decreased side-
Publicado em: 2007
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19. "Aplicação de catalisadores de níquel e cobalto preparados via precursores do tipo hidrotalcita nas reações de reforma a vapor, oxidação parcial e reforma oxidativa do metano" / "Application of nickel and cobalt catalysts prepared via hydrotalcite-type precursors in the reactions of steam reforming, partial oxidation and oxidative reforming of methane"
One of the most important applications of methane is the syngas production, a mixture of H2 and CO. Three processes can lead to syngas formation from methane: steam reforming, CO2 reforming and partial oxidation. Various non-noble metal catalysts were studied in these processes, although the carbon deposition or the metal sinterization is always observed. Ca
Publicado em: 2007
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20. Desenvolvimento de catalisadores de ródio e cobalto para a reforma a vapor do etanol.
The development of technologies based on the use of biofuels has taken the attention of the scientific community, due to the current dependence on fossil fuels, which results in an increase of air pollution. This pollution increase is related to public health problems and climate changes. In this context, the use of fuel cells moved by hydrogen is a mean of
Publicado em: 2007
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21. Intercalação de fármacos com atividade antiinflamatória (ácido mefenâmico e piroxicam) em hidróxido duplo lamelar / Intercalation of drugs with antiinflammatory activity (mefenamic acid and piroxicam) in layered double hydroxide
A intercalação de espécies de interesse biológico e terapêutico em Hidróxidos Duplos Lamelares (HDLs) vem se mostrando uma estratégia interessante para a obtenção de sistemas de armazenamento ou carregadores de drogas. No presente trabalho foram investigadas rotas sintéticas e parâmetros experimentais para a intercalação dos ânions derivados do
Publicado em: 2007
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22. Vanadium oxides supported on hydrotalcite-type precursors: the effect of acid-base properties on the oxidation of isopropanol
Vanadium oxide supported on hydrotalcite-type precursors was studied in the oxidation of isopropanol. Hydrotalcites with different y = Mg/Al ratios were synthesized by the method of coprecipitation nitrates of Mg and Al cations with K2CO3 as precipitant. The decomposition of these hydrotalcite precursors at 450°C yielded homogeneous MgyAlOx mixed oxides tha
Brazilian Journal of Chemical Engineering. Publicado em: 2006-09
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23. 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
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24. Influence of thermal treatments on the basic and catalytic properties of Mg,Al-mixed oxides derived from hydrotalcites
This work studied the influence of calcination conditions on basic properties and catalytic performance of Mg,Al-mixed oxides derived from a hydrotalcite sample (Al/(Al+Mg)=0.20). Various heating rates, calcination atmospheres and lengths of calcination at 723K were evaluated. TPD of CO2 and retroaldolization of diacetone alcohol (DAA) were used to determine
Brazilian Journal of Chemical Engineering. Publicado em: 2004-06