Tunable nanosized spinel manganese ferrites synthesized by solution combustion method

Abstract

The influence of the glycine-glycerol fuel mixing ratio on the structure, morphology, magnetic and catalytic properties of nanosized MnFe2O4 prepared by solution combustion method was investigated. The samples were synthesized using mixture of glycerol and glycine in the reducing power ratios 1:0, 0.75:0.25, 0.5:0.5, and 0.25:0.75. All samples were characterized by powder X-ray diffraction, N2-physisorption at 77 K, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy and H2-thermal programmed reduction. Magnetic behavior of the ferrites at room temperature was investigated. It was demonstrated that by varying the glycerol to glycine ratio, samples with different magnetic properties can be prepared. The catalytic properties of MnFe2O4 were studied in reactions of complete oxidation of hydrocarbons (methane, ethane, propane, butane) as model substances. The results reveal that structural, surface and morphological characteristics of the prepared spinels could be tuned by varying the ratios in the fuel mixtures. The nanoparticles obtained with glycerol and with a mixture fuel with glycine up to 50% show better catalytic oxidation properties than the sample obtained with a fuel containing 75% glycine. After the catalytic tests these samples do not undergo any substantial phase and morphological changes, thus they could be applied in low temperature combustion.