Preparation of Monolithic LaFeO3 and Catalytic Oxidation of Toluene.

Abstract

Porous LaFeO3 powders were produced by high-temperature calcination of LaFeO3 precursors obtained by hydrothermal treatment of corresponding nitrates in the presence of citric acid. Four LaFeO3 powders calcinated at different temperatures were mixed with appropriate amounts of kaolinite, carboxymethyl cellulose, glycerol and active carbon for the preparation of monolithic LaFeO3 by extrusion. Porous LaFeO3 powders were characterized using powder X-ray diffraction, scanning electron microscopy, nitrogen absorption/desorption and X-ray photoelectron spectroscopy. Among the four monolithic LaFeO3 catalysts, the catalyst calcinated at 700 °C showed the best catalytic activity for the catalytic oxidation of toluene at 36,000 mL/(g∙h), and the corresponding T10%, T50% and T90% was 76 °C, 253 °C and 420 °C, respectively. The catalytic performance is attributed to the larger specific surface area (23.41 m2/g), higher surface adsorption of oxygen concentration and larger Fe2+/Fe3+ ratio associated with LaFeO3 calcined at 700 °C.