Chemical Interaction Between MgO Support and Iron Catalyst

In this paper, the chemical interaction between catalyst and support was studied to understand the observed different growth rate of CNTs in our previous paper. Both pure MgO and Mg(NO3)(2)center dot 6H(2)O as sources of the MgO catalyst support and Fe-2(SO4)(3) center dot xH(2)O as the source of the Fe catalyst, were employed. A Fe catalyst supported on MgO was synthesized using the wet impregnation method followed by calcination. To compare the catalyst grain size and its distribution, the sample were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray powder diffraction (XRD), BET specific surface area (SSA) measurement, and X-ray photoelectron spectroscopy (XPS). XPS technique was utilized complementary to demonstrate the existence of chemical interaction between MgO support and Fe catalyst. Results revealed that the type of precursor used to prepare the support had a significant influence on the morphology of the support and the associated distribution of the Fe catalysts. The highest yield of MgFe2O4 phase was obtained using a pure MgO precursor which after calcination resulted in a homogenous distribution of nano-sized Fe particles over the support surface.