Abstract
Spinel-type CoMn2O4nano-powders are prepared using sol-gel auto combustion (SGC) and co-precipitation (CP) methods and their catalytic activities are evaluated in combustion of 2-propanol and toluene. The chemical-physical properties of the oxides are characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), N2-adsorption-desorption, temperature programmed reduction (TPR) and scanning electron microscopy (SEM). After calcination at 700°C, CoMn2O4-SGC shows higher amounts of the normal-type spinel phase and is more crystalline than CoMn2O4-CP. Higher calcination temperatures (850°C) do not affect very much the weight percentage of the normal-type spinel phase; although the crystal size slightly increased. The TPR analysis evidences a large number of Mn3+ cations in CoMn2O4-SGC compared to CoMn2O4-CP. This difference, together with the higher surface area, could justify the higher activity of CoMn2O4-SGC in both the investigated reactions.
Acknowledgements
The authors are thankful to those who contributed to enhancing this project, especially Iranian Nanotechnology Initiative Council for financial support and the Institute for the Study of Nanostructured Materials (ISMN) of the National Research Council (CNR) of Italy for the collaboration in this work.