Synthesis and activity tests of nano Perovskite catalysts for CO combustion

Modified perovskite-type oxides were synthesized based on two different methods,namely co-precipitation and conventional citrate.The synthesized perovskite materials had the nominal composition s of LaCoO3,LaCo0.8Cu0.2O3,La0.8Sr0.2Co0.8Cu0.2O3,La0.8M0.2Fe0.8O3 (where M =Ce and Sr).The catalytic activity of perovskite samples toward CO combustion were measured using a gas mixture containing N2/O2/CO in the following proportions 97/1/2.The prepared perovskite samples were characterized by SEM,nitrogen adsorption (BET),XRF and XRD analyses.All the catalysts displayed good stability above 600°C and a high activity toward CO combustion.Our novel proposed perovskite composition,namely La0.8Sr0.2Co0.8Cu0.2O3 showed the highest activity for achieving CO conversion above 80%.While homogeneous gas-phase combustion of CO requires temperatures in excess of 700°C to achieve fair kinetics,our novel catalyst sample achieved 100%CO combustion at 355°C.

Keywords:

Combustion , Perovskite , catalyst , CO , lanthanum , cobalt , activity