304 resultados para MOF@carbón


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Las grandes emisiones de CO2 procedentes de la combustión de combustibles fósiles están provocando un calentamiento global en nuestro planeta. Estos problemas medioambientales están obligando a los diferentes gobiernos a buscar soluciones que permitan reducir esas emisiones y mitigar sus efectos adversos. Una de las soluciones más prometedoras consiste en la captura selectiva de CO2 en efluentes industriales mediante el uso de materiales adsorbentes porosos (zeolitas, carbón activado y materiales híbridos MOFs) que combinen una elevada capacidad de adsorción y una adecuada selectividad a CO2 frente al resto de gases del proceso industrial, además de una adecuada regeneración.

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The kinetic study of decomposition of hydrogen peroxide catalyzed by activated carbon was carried out. The effect of concentrations of reactants and temperature were experimentally studied. Kinetic data were evaluated using differential method of initial rates of reaction. When a typical kinetic law for reactions in homogeneous phase is used, first order of reaction is obtained for hydrogen peroxide and activated carbon, and activation energy of 27 kJ mol-1 for the reaction was estimated. Experimentally was observed that surface of activated carbon is chemically modified during decomposition of hydrogen peroxide, based on this result a scheme of reaction was proposed and evaluated. Experimental data fits very well to a Langmuir- Hinshelwood kinetic model and activation energy of 40 kJ mol-1 was estimated for reaction in heterogeneous phase.

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Low-rank coals are an important source of humic acids, which are important in retention processes of water and nutrients in plants. In this study coal samples of Montelibano, Colombia, were oxidized with air at different temperatures and subsequently with H2O2 and HNO3. The materials were characterized by FTIR, proximate and elemental analysis, and quantification of humic acids. The oxidation process led to an increased content of oxygenated groups and humic acids in the carbonaceous structure. The solid oxidized with air at 200 ºC for 12 h and re-oxidized with HNO3 for 12 h showed the highest percentage of humic acids (85.3%).

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We used conceptual DFT to study global and local reactivity of both nonfunctionalized and functionalized activated carbons, with groups -OH,-CHO, -NH2, -COOH, and -CONH2. Electron-withdrawing groups were observed to increase the reactive surface, while electro-donating groups increase stability as reactivity of the activated carbon decreases. Descriptor groups were used to study the reactivity of structural fragments of activated carbons. The electrophilic and nucleophilic sites indicate that the carbon surface has an amphiphilic behavior that allows it to be used as an adsorbent material for a variety of molecules.

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Tesis (Maestro en Ciencias de la Administración con Especialidad en Sistemas) UANL, 1999.

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Tesis (Maestría en Ciencias de la Administración con Especialidad en Producción y Calidad) - U.A.N.L, 2000

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Tesis (Maestro en Ciencias de la Administración con Especialidad en Producción y Calidad) UANL, 2000

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Tesis (Maestría en Ciencias de la Administración con Especialidad en Producción y Calidad) - U.A.N.L, 2000

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Tesis (Maestro en Ciencias Químicas con Especialidad en Química Analítica) U.A.N.L.

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Tesis (Maestro en Ciencias Especialidad en Ingeniería Ambiental) UANL, 2007.

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Tesis (Maestría en Ciencias con Orientación en Procesos Sustentables) UANL, 2012.

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Tesis (Maestría en Ciencias con Orientación en Procesos Sustentables) UANL, 2010.

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Tesis (Maestría en Ciencias con Orientación en Procesos Sustentables) UANL, 2012.