Effect of preparation methods on the catalytic activity of La0.9Sr0.1CoO3 perovskite for CO and C3H6 oxidation

Abstract

La0.9Sr0.1CoO3 perovskite oxides were prepared by a hard template and a sol-gel method, respectively. The catalytic activities for oxidation of CO and C3H6 were examined. XRD, BET, TEM, TPR, and TGA techniques have been used to characterize structural properties, reducibility, mobility of lattice oxygen, and oxygen release rate. La0.9Sr0.1CoO3 synthesized by the hard template (SBA-15) method had a higher surface area and smaller particle size, providing more surface adsorbed oxygen. TPR and TGA results showed that oxygen in La0.9Sr0.1CoO3 prepared by the hard template method can be more easily extracted in H2 atmosphere than oxygen in the sol-gel prepared sample. These improved properties of La0.9Sr0.1CoO3 synthesized by the hard template (SBA-15) method facilitate catalytic oxidation reactions resulting in enhanced light-off performance for oxidation of CO or C3H6 compared to the sample prepared by the sol-gel method. Furthermore, the La0.9Sr0.1CoO3 catalyst prepared by the hard template method showed improved activity for the simultaneous oxidation of CO and C3H6 under simulated diesel exhaust conditions. Both catalysts showed almost no deactivation after 48 h on stream.