Highly active titania supported ceria catalysts for ammoxidation of picolines

Abstract

TiO 2 supported ceria catalysts with 20 wt% CeO 2 were prepared by impregnating rutile and anatase polymorphs in aqueous solution of ammonium ceric nitrate [(NH 4) 2Ce(NO 3) 6], characterized by BET surface area measurement and low temperature oxygen chemisorption (LTOC) at −78°C and evaluated for ammoxidation of β- and γ-picolines. Anatase supported catalyst has exhibited higher ammoxidation activities than rutile supported one and pure ceria. Turnover frequencies calculated from ammoxidation rates and irreversible O 2 uptakes in respect to a particular picoline isomer were almost equal for pure supports on one hand and for supported ceria catalysts on the other. The two structural isomers, β- and γ-picolines seem to have exhibited marked steric effect in their reactivity in catalysis on the catalysts.