Journal Articles (before-1995)

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    Characterization of the Hydroxyls in Offretitc Zeolite
    (Journal of the Chemical Society : Faraday Transaction - I. The Chemical Society, London. 1978, 74 (07), 1978) Mirodatos, Claude; Abou-Kais, Antoine; Vedrine, Jacques C.; Barthomeuf, Denise
    It is shown that three structural hydroxyl groups are generated in offretite upon cation exchange. The 3660 cm–1 OH groups are either not acidic or only slightly so and are probably located in the inaccessible hexagonal prism (O6H). The 3610 and 3550 cm–1 hydroxyls are acidic. Their strength increases at low cation content. The 3610 cm–1 groups are mainly located in the channel (O5H) while the low frequency groups are suggested to be in the cancrinite cage (O2H or O4H).
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    Electron paramagnetic resonance study of hydrogen atoms trapped in γ-irradiated Y type zeolites exchanged with different cations
    (Journal of the Chemical Society : Faraday Transaction - I. The Chemical Society, London. 1974, 70 (1-6), 1974) Abou-Kais, Antoine; Vedrine, Jacques C.; Massardier, Jean; Dalmai-Imelik, Gisele
    H atoms trapped after the γ-irradiation at 77 K of Y type zeolites exchanged with different cations have been studied using e.p.r. spectroscopy. The H atom yield is dependent on the acidic structural OH group content and it is postulated that the mechanism of formation and trapping of H atoms follows the following equilibrium: [graphic omitted] The H atom yield is related to the acidity and mobility of the hydrogen of the hydrogen of the hydroxyl groups and to the trapping strength. The trapping strength of H atoms, characterized by the values of both the hyperfine coupling constant with respect to the free H atom, and the activation energy of recombination, is strongly dependent on the nature of the exchanged cation, and follows the sequence K > Na [double greater-than, compressed] Ca > La.