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 COMPOSITIONS OF LACOO₃, LACO_0.8CU_0.2O₃, LA_0.8SR_0.2CO_0.8CU_0.2O₃, LA_0.8M_0.2FE_0.8O₃ (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 LA_0.8SR_0.2CO_0.8CU_0.2O₃ 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.