Journal of the Serbian Chemical Society 2011 Volume 76, Issue 12, Pages: 1661-1671
https://doi.org/10.2298/JSC110429149H
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Mg-Fe-mixed oxides derived from layered double hydroxides: A study of the surface properties
Hadnađev-Kostić Milica S. (Faculty of Technology, Novi Sad)
Vulić Tatjana J. (Faculty of Technology, Novi Sad)
Marinković-Nedučin Radmila P. (Faculty of Technology, Novi Sad)
Nikolić Aleksandar D. (Faculty of Science, Novi Sad)
Jović Branislav (Faculty of Science, Novi Sad)
The influence of surface properties on the selectivity of the synthesized
catalysts was studied, considering that their selectivity towards particular
hydrocarbons is crucial for their overall activity in the chosen Fischer-
-Tropsch reaction. Magnesium- and iron-containing layered double hydroxides
(LDH), with the general formula: [Mg1-xFex(OH)2](CO3)x/2?mH2O, x = =
n(Fe)/(n(Mg)+n(Fe)), synthesized with different Mg/Fe ratio and their
thermally derived mixed oxides were investigated. Magnesium was chosen
because of its basic properties, whereas iron was selected due to its
well-known high Fischer-Tropsch activity, redox properties and the ability to
form specific active sites in the layered LDH structure required for
catalytic application. The thermally less stable multiphase system
(synthesized outside the optimal single LDH phase range with additional
Fe-phase), having a lower content of surface acid and base active sites, a
lower surface area and smaller fraction of smaller mesopores, showed higher
selectivity in the Fischer-Tropsch reaction. The results of this study imply
that the metastability of derived multiphase oxides structure has a greater
influence on the formation of specific catalyst surface sites than other
investigated surface properties.
Keywords: Mg-Fe-LDHs, hydrotalcite, acid-base properties, Fischer-Tropschreaction, selectivity