Browsing by Autor "Jamal El Haskouri"

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    Enhanced manganese content in Mn-MCM-41 mesoporous silicas
    (Springer Science+Business Media, 2005) Jamal El Haskouri; Saúl Cabrera; Aurelio Beltrán; Carmen Guillem; D. Beltrán; J. Latorre; M. Dolores Marcos; Pedro Amorós
    The use of triethanolamine containing complexes of Si and Mn as hydrolytic precursors allows the synthesis of doped mesoporous silicas in which the Mn content can be modulated up to reach a minimum value of the Si/Mn molar ratio of 3. This limit value corresponds to a Mn relative content significantly higher than those reported to date for similar materials (Si/Mn = 6). According to XRD, TEM and porosity data, the mesoporous nature typical of the MCM-41 silicas is retained even for the samples having the highest Mn content.
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    One‐Pot Synthesis of Superparamagnetic CoO‐MCM‐41 Nanocomposites with Uniform and Highly Dispersed Magnetic Nanoclusters
    (Wiley, 2004) Jamal El Haskouri; Saúl Cabrera; Carmen Guillem; Julio Latorre; Aurelio Beltrán; M. Dolores Marcos; Carlos J. Gómez‐García; Daniel Beltrán; Pedro Amorós
    Abstract Superparamagnetic CoO‐MCM‐41 mesoporous nanocomposites, with variable cobalt amounts, in the form of well‐dispersed CoO‐like clusters, were prepared in a large compositional range by a one‐step reproducible procedure employing co‐hydrolysis and co‐condensation of the inorganic precursors in a water/triethanolamine medium. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
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    Ordered mesoporous materials: composition and topology control through chemistry
    (Elsevier BV, 2001) Jamal El Haskouri; Saúl Cabrera; Maria Teresa Caldés; Jesús A. del Alamo; Aurelio Beltrán; M. Dolores Marcos; Pedro Amorós; Aurelio Beltrán
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    Ordered Mesoporous Silicon Oxynitrides
    (2001) Jamal El Haskouri; Saúl Cabrera; Fernando Sapiña; J. Latorre; Carmen Guillem; Aurelio Beltrán; Aurelio Beltrán; M. Dolores Marcos; Pedro Amorós
    The functionalization of mesostructured and/or mesoporous MCM-41 related silicas is easily achieved by treatment under NH3 atmosphere at relatively low temperatures without structural collapse. Nitridation, which occurs through a single-step solid-state reaction, yields for the first time ordered mesoporous silicon oxynitrides with high surface area (see Figure).
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    Very high titanium content mesoporous silicas
    (Royal Society of Chemistry, 2001) Jamal El Haskouri; Margarita Gutiérrez; Aurelio Beltrán; Aurelio Beltrán; Pedro Amorós; Saúl Cabrera; M. Dolores Marcos
    Titanium content in mesoporous titanosilicate catalysts has been modulated up to a minimum Si/Ti value of 1.9 by using complexing agents able to coordinate both Si and Ti atoms and harmonize the reactivity of the resulting precursors avoiding subsequent phase segregation and leading to chemically very homogeneous materials.