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Direct Synthesis of Zr‐Containing Hybrid Periodic Mesoporous Organosilicas with Tunable Zirconium Content
Author(s) -
Zhai ShangRu,
Park Sung Soo,
Park Mina,
Ullah M. Habib,
Ha ChangSik
Publication year - 2007
Publication title -
european journal of inorganic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 1434-1948
DOI - 10.1002/ejic.200700775
Subject(s) - zirconium , chemistry , x ray photoelectron spectroscopy , molar ratio , mesoporous material , sorption , mesoporous organosilica , hybrid material , chemical engineering , small angle x ray scattering , inorganic chemistry , nuclear chemistry , mesoporous silica , organic chemistry , catalysis , adsorption , scattering , engineering , physics , optics
Highly ordered Zr‐containing periodic mesoporous organosilicas (ZrPMO) with different Zr/Si ratios were successfully synthesized, for the first time, by employing a ZrOCl 2 /NaCl combination as the promoting agent and by simply adjusting the molar ratio of the zirconium species to the organosilica precursor; no addition of mineral acids was necessary. The effect of preparation parameters on the structural and textural properties were carefully investigated by using different ratios of NaCl/Si and Zr/Si. It was found that both salts are essential for this system and highly ordered ZrPMOs can be prepared within fairly wide Si/Zr ratios (5–100) while keeping the NaCl/Si ratio constant. To prove the effectiveness of this synthetic pathway with a higher Zr incorporation, ZrPMO materials were also synthesized under strongly acidic conditions for the purpose of comparison. The synthesized ZrPMO materials were thoroughly characterized by ICP‐AES, SAXS, N 2 sorption, TEM, SEM, 13 C CP/ 29 Si MAS NMR spectroscopy, XPS, and TGA. Elemental analyses show that the amount of Zr incorporated into ZrPMO, which was synthesized under mild conditions, is greater than that obtained in a strongly acidic environment, and the Zr content, with a Si/Zr ratio up to 12, is close to that in the initial gel composition. A plausible assembly mechanism based on the synergistic effect of both “nonhydrolyzable” (NaCl) and “hydrolyzable” (ZrOCl 2 ) inorganic salts was discussed in detail, where the “salting out” effect and self‐generated acidity from both inorganic salts, respectively, are believed to be key factors for the formation of ordered SBA‐15‐type ZrPMO materials under the synthetic conditions.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)