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  • XAS studies on incorporation of Mn and Co into silicalite-1
    Arčon, Iztok ...
    Mn and Co containing silicalite1 MnS1 and CoS1 were synthesized hydrothermally.Templatefree samples were obtained by calcination at 550C for 6hours in oxygen flow. Xray diffraction, elemental, ... thermogravimetric and cation exchange analyses suggested a possible incorporation of Mn and Co cations into the framework positions of the silicalite1. The valence state andlocal environment of both cations in the samples were examined by XANES andEXAFS analyses. Results show that Mn and Co cations isomorphously substitute silicon in the silicalite1 framework only if they are in trivalent oxidation state. Divalent cations are incorporated on extraframework positions. In the templatefree MnS1 sample all Mn cations are in trivalent state and substitute Si in the framework, forming a distorted and coordinatively unsaturated 3fold symmetry, which is characteristic for Lewis acid sites. In the templatefree CoS1 sample only part of Co cations are in trivalent state substituting silicon in the framework.
    Vrsta gradiva - prispevek na konferenci
    Leto - 2005
    Jezik - angleški
    COBISS.SI-ID - 3265818