Fe(III)-modified montmorillonite and bentonite : Synthesis, chemical and UV-Vis spectral characterization, arsenic sorption, and catalysis of oxidative dehydrogenation of propane
Grygar, T. (Institute of Inorganic Chemistry ASCR)
Hradil, D. (Institute of Inorganic Chemistry ASCR)
Bezdička, P. (Institute of Inorganic Chemistry ASCR)
Doušová, B. (Institute of Chemical Technology in Prague)
Čapek, L. (University Pardubice)
Schneeweiss, O. (Institute of Physics of Materials ASCR)

Data:	2007
Resum:	Two major species were identified in Fe-treated montmorillonite: monomeric or dimeric hydroxoaqua cations Fe(OH) - (form I), and polymeric structures with edge-shared Fe(O,OH) (form II). These species have different electron spectra (absorption maximum is 29,600 cm in form I, and 26,000 and 28,000 cm in form II), chemical and thermal stability, and electrochemical behavior. Form I behaves as a partly exchangeable cation in interaction with Cu from Cu-trien solution and Ni from Ni-EDTA, that can be used for selective quantitative analysis. On heating above the dehydration temperature (∼100-150°C) montmorrilonite with Fe in form I is converted to a mica-like structure and Fe ions are fixed more strongly in the montmorillonite structure. Form II behaves similarly to hydrous ferric oxides, but its thermal crystallization to hematite is postponed to ∼500-600°C. The Fe cations in the interlayer space are much less thermally stable than Al pillars in pillared interlayered clays (PILCs). Form I is more active in oxidative dehydrogenation of propane, while form II is the active species in sorption of As and the non-specific combustion of propane. To produce only form II by the treatment of montmorillonite with Fe, its load must be kept below ∼20 wt. %; otherwise the usual hydrous ferric oxides are formed.
Drets:	Aquest material està protegit per drets d'autor i/o drets afins. Podeu utilitzar aquest material en funció del que permet la legislació de drets d'autor i drets afins d'aplicació al vostre cas. Per a d'altres usos heu d'obtenir permís del(s) titular(s) de drets.
Llengua:	Anglès
Document:	Article ; recerca ; Versió publicada
Matèria:	As sorption ; Fe-montmorillonite ; Fe-bentonite ; Oxidative Dehydrogenation of Propane ; Pillaring ; Speciation of Fe
Publicat a:	Clays and Clay Minerals, Vol. 55, Núm. 2 (2007) , p. 165-176, ISSN 1552-8367

DOI: 10.1346/CCMN.2007.0550206

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