Mechanochemical synthesis of highly dispersed iron oxide from metallic powders in manufacture of catalysts

Abstract

X-ray phase, X-ray diffraction, and synchronous thermal analyses, Mossbauer and IR spectroscopy, and scanning electron microscopy were used to study processes occurring in the stages of mechanochemical oxidation and thermal treatment of coarsely dispersed iron and cast iron powders in a dispersion medium of water and oxalic acid solutions. The optimal mechanochemical-synthesis conditions were determined and it was found that the preparation method affects the phase composition, structure, and properties of the resulting oxides. It was experimentally confirmed that the mechanochemical oxidation method makes it possible to obtain oxides by the zero-sewage technology with a specific surface area 1.5–12 times larger that that in oxides produced by the conventional precipitation technique. An analysis of the reactivity of the samples in the model reaction of carbon monoxide conversion by steam demonstrated their high catalytic activity.