50 research outputs found

    New record of Sphenopid Zoanthid species Palythoa tuberculosa (Esper, 1805) from Gulf of Mannar, India

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    347-350Coral reefs provide a suitable habitat for many marine flora and fauna. Zoanthid is one of the most common inhabitants in coral reef habitats. A sub-massive colony of Sphenopid Zoanthid species Palythoa tuberculosa belonging to the order Zoantharia was documented for the first time from Gulf of Mannar (GoM) during an intensive coral reef monitoring survey conducted in Manoli, Manoliputti and Shingle Island. Photographic evidence of the colony along with its morphological characteristics are described in the present study

    Liquid Phase Hydrogenation of Pharmaceutical Interest Nitroarenes over Gold-Supported Alumina Nanowires Catalysts

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    In this work, Au nanoparticles, supported in Al2O3 nanowires (ANW) modified with (3-aminopropyl)trimethoxysilane were synthetized, for their use as catalysts in the hydrogenation reaction of 4-(2-fluoro-4-nitrophenyl)-morpholine and 4-(4-nitrophenyl)morpholin-3-one. ANW was obtained by hydrothermal techniques and the metal was incorporated by the reduction of the precursor with NaBH4 posterior to superficial modification. The catalysts were prepared at different metal loadings and were characterized by different techniques. The characterization revealed structured materials in the form of nanowires and a successful superficial modification. All catalysts show that Au is in a reduced state and the shape of the nanoparticles is spherical, with high metal dispersion and size distributions from 3.7 to 4.6 nm. The different systems supported in modified-ANW were active and selective in the hydrogenation reaction of both substrates, finding for all catalytic systems a selectivity of almost 100% to the aromatic amine. Catalytic data showed pseudo first-order kinetics with respect to the substrate for all experimental conditions used in this work. The solvent plays an important role in the activity and selectivity of the catalyst, where the highest efficiency and operational stability was achieved when ethanol was used as the solventIndexación: Scopu

    Nanocatalizadores metálicos soportados en estructuras 0d y 1d con aplicaciones en química fina

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    El desafío actual en el diseño racional de catalizadores aplicados en la producción de compuestos químicos de alto valor agregado radica en la preparación de sistemas que sean capaces de operar en ciclos catalíticos consecutivos manteniendo una alta actividad y selectividad en la producción del compuesto de interés.Centro de Investigación y Desarrollo en Ciencias Aplicada

    Nanocatalizadores metálicos soportados en estructuras 0d y 1d con aplicaciones en química fina

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    El desafío actual en el diseño racional de catalizadores aplicados en la producción de compuestos químicos de alto valor agregado radica en la preparación de sistemas que sean capaces de operar en ciclos catalíticos consecutivos manteniendo una alta actividad y selectividad en la producción del compuesto de interés.Centro de Investigación y Desarrollo en Ciencias Aplicada

    Catalytic pyrolysis of used tires on noble-metal-based catalysts to obtain high-value chemicals: Reaction pathways

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    A systematic study on the use of noble metals (Pd, Pt, Au) supported on titanate nanotubes (NT-Ti) for selectively producing BTX and p-cymene from waste tire pyrolysis is provided here. All the materials were characterized for chemical, textural and structural properties using a range of analytical techniques. The M/NT-Ti (M: Pd, Pt, or Au) catalysts exhibit low nanoparticle sizes (1.8 Pt ≈ Au > support > non-catalyst. The Py-GC/MS suggest that the catalysts participate in the secondary reactions of dealkylation, dehydrogenation, isomerization, aromatization, and cyclization leading to a higher formation of BTX than the uncatalyzed reaction. Finally, a comprehensive reaction pathway describing the catalytic pyrolysis of WT over Pd/NT-Ti was proposed by studying the catalytic pyrolysis of individual polymers constituting the waste tires, and D,L-Limonene.Puede accederse a los datos primarios de este trabajo haciendo clic en "Documentos relacionados".Centro de Investigación y Desarrollo en Ciencias Aplicada
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