Nanocrystalline Mixed Oxides Containing Magnesium Prepared by a Combined Sol-Gel and Self-Combustion Method for Catalyst Applications

Nicolae Rezlescu, Elena Rezlescu, Liliana Sachelarie, Paul Dorin Popa, Corneliu Doroftei, Maria Ignat

Al. I. Cuza University, Iasi, Romania.
Apolonia University, Iasi, Romania.
National Institute of Research and Development for Technical Physics, Iasi, Romania.

DOI: 10.4236/msa.2013.48054                

Abstract

MgFe₂O₄ spinel ferrite and La_0.6Pb_0.2Mg_0.2MnO₃ perovskite nanopowders were synthesized by a combined sol-gel and self-combustion method and heat treatment. The morphological and structural characterization of the obtained powders has been performed with various techniques: X-ray diffraction (XRD), SEM observations, EDAX spectroscopy and BET analysis. The samples have been catalytically tested in flameless combustion reaction of acetone, benzene, propane and Pb free gasoline at atmospheric pressure. The results revealed a higher catalytic activity of La_0.6Pb_0.2Mg_0.2 MnO₃ perovskite than that of MgFe₂O₄ ferrite. This higher catalytic activity can be ascribed to smaller crystallite size (27 nm), larger surface area (8.5 m²/g) and the presence of manganese cations with variable valence (Mn³⁺ - Mn⁴⁺). The current results suggest that La_0.6Pb_0.2Mg_0.2MnO₃ perovskite is preferable to the Mg ferrite and that it can be a promising catalyst for acetone and propane combustion at low temperatures.

 

Keywords

Oxides; Sol-Gel-Self-Combustion; Microstructure; SEM; XRD; Catalytic Properties

Conflicts of Interest

The authors declare no conflicts of interest.

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