| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 71981 | Microporous and Mesoporous Materials | 2016 | 16 Pages |
•New post-synthesis impregnation with pressure assistance for PCH doping was shown.•Structural rearrangements in FePCH composites derived from Laponite were described.•Use of autoclaving ensures better dispersion of Fe nanostructures on the PCH surface.•Fe embedding into PCH lattice caused increase of the average pore diameter.
In this study novel approach of Fe doped porous clay heterostructures synthesis by iron incorporation from the inorganic Fe(NO3)3·9H2O and metal-organic C6H5FeO sources, via post-synthesis route and pressure assistance, was described. Although post-synthesis impregnation proved to be sufficient method of porous clay heterostructures functionalization with iron species, the use of autoclaving ensured better dispersion of Fe nanostructures on the surface of clay derived supports. Appropriate choice of iron source was also essential to control formation of surface and sub-surface Fe species and incorporation of Fe into the selected lattice sites of the composite. The presence of ultrafine crystallites of α-Fe2O3 and Fe3O4 phases by TEM analysis supporting XRD measurement was evidenced. It turns out that high pressure treatment facilitated migration of trivalent heterocations along the composite network. It caused even complete iron embedding into the bulk/sub-surface lattice. The temperature transformation and pressure treatment not only influenced the composition and dispersion of the surface Fe species. It caused structure evolution of PCH composite, modification its textural properties, the increase of the average pore diameter (from 2.6 nm in PCH to 3.7 nm in FePCH-nit/aut and 4.5 nm in FePCH-cit/aut). Those phenomena influenced the catalytic activity of studied samples in ethanol decomposition. Transmission and reflection FTIR techniques in MIR and NIR regions, 57Fe Mössbauer and 29Si MAS-NMR spectroscopies were used to describe the structural rearrangements of PCH composites derived from Laponite® upon modified post-synthesis introduction of Fe and to distinguish between different species of Fe highly dispersed on the extended PCH surface.
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