La1−xCexMn1−yCoyO3 perovskite oxides: Preparation, physico-chemical properties and catalytic activity for the reduction of diesel soot.

La 1− x Ce x Mn 1− y Co y O 3 catalysts were prepared by the “glucose method”. The structures and physico-chemical properties for these catalysts were characterized using X-ray diffraction (XRD), nitrogen adsorption, scanning electron microscopy (SEM), Fourier transform infrared spectra (FT-IR), H 2 -temperature-programmed reduction (H 2 -TPR) and O 2 -tempreature-programmed desorption (O 2 -TPD). Results showed that cerium substitution at the A-site in LaMnO 3 produced a CeO 2 phase. The cobalt can be introduced into the B-site in La 0.8 Ce 0.2 MnO 3 at any substitution ratio because of the similar ionic radii between cobalt and manganese. The catalytic activity for soot combustion in air was evaluated using a TG/DTA analyzer. Cerium substitution at A-site enhances the catalytic activity, while cobalt substitution at B-site inhibits the catalytic activity. The activation energy for soot combustion was calculated using the Horowitz method. The activation energy for non-catalytic soot combustion was 164.1 kJ mol − 1 . The addition of catalysts decreased the activation energy by about 26–63 kJ mol − 1 . Among the applied catalysts, Ce20Mn exhibited the lowest activation energy (101.1 kJ mol − 1 ). [ABSTRACT FROM AUTHOR]