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Materials 2009, 2(4), 2337-2359; doi:10.3390/ma2042337
Article

Highly Loaded Fe-MCM-41 Materials: Synthesis and Reducibility Studies

1
 and 2,*
Received: 4 November 2009; in revised form: 30 November 2009 / Accepted: 14 December 2009 / Published: 15 December 2009
(This article belongs to the Special Issue Porous Materials)
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Abstract: Fe-MCM-41 materials were prepared by different methods. The Fe was both incorporated into the structure and formed crystallites attached to the silica. High Fe content MCM-41 (~16 wt%) with retention of mesoporosity and long-range order was achieved by a range of new synthetic methodologies: (i) by delaying the addition of Fe3+(aq) to the stirred synthesis gel by 2 h, (ii) by addition of Fe3+ precursor as a freshlyprecipitated aqueous slurry, (iii) by exploiting a secondary synthesis with Si-MCM-41 as SiO2 source. For comparative purposes the MCM-41 was also prepared by incipient wetness impregnation (IWI). Although all these synthesis methods preserved mesoporosity and long-range order of the SiO2 matrix, the hydrothermally-fabricated Fe materials prepared via the secondary synthesis route has the most useful properties for exploitation as a catalyst, in terms of hydrothermal stability of the resulting support. Temperatureprogrammed reduction (TPR) studies revealed a three-peak reduction pattern for this material instead of the commonly observed two-peak reduction pattern. The three peaks showed variable intensity that related to the presence of two components: crystalline Fe2O3 and Fe embedded in the SiO2 matrix (on the basis of ESR studies). The role of secondary synthesis of Si-MCM-41 on the iron reducibility was also demonstrated in IWI of sec-Si-MCM-41.
Keywords: Fe-MCM-41; secondary synthesis; temperature programmed reduction; wustite (FeO); incipient wetness impregnation Fe-MCM-41; secondary synthesis; temperature programmed reduction; wustite (FeO); incipient wetness impregnation
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

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MDPI and ACS Style

Mokhonoana, M.P.; Coville, N.J. Highly Loaded Fe-MCM-41 Materials: Synthesis and Reducibility Studies. Materials 2009, 2, 2337-2359.

AMA Style

Mokhonoana MP, Coville NJ. Highly Loaded Fe-MCM-41 Materials: Synthesis and Reducibility Studies. Materials. 2009; 2(4):2337-2359.

Chicago/Turabian Style

Mokhonoana, Malose P.; Coville, Neil J. 2009. "Highly Loaded Fe-MCM-41 Materials: Synthesis and Reducibility Studies." Materials 2, no. 4: 2337-2359.


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