Catalytic performance and structural features of LaxBa1-xFeO3 perovskites for automotive exhaust gas treatment

Perovskites have recently gained significant attention as a cost-effective alternative to noble metals in automotive catalytic converters. In this study, a series of La x Ba 1-x FeO 3 perovskites was prepared via the sol–gel approach and subjected to comprehensive characterization, including XRD, FT-IR, XPS, H 2 -TPR, FESEM, TEM, and N 2 physisorption measurements. The efficiency and performance of the synthesized perovskites were evaluated on the treatment of the automotive exhaust gas through the reactor test. The CO conversion started at a lower temperature than C 3 H 8 and NO. The conversion of CO started at 100°C, for NO began from 150°C, and for C 3 H 8 started from 200°C for LaFeO 3 perovskite. The conversion of CO was reached to 100% at about 275°C, and for C 3 H 8 was about 360 °C for LaFeO 3 perovskite. The results showed that partially substituting La 3+ with Ba 2+ improved the CO and hydrocarbon oxidation at low temperatures, and Ba-containing perovskites reached the maximum activity faster in comparison with LaFeO 3 . Also, the catalyst's performance showed that Ba-containing perovskites had higher activity in the NO x reduction, and partially substituting La 3+ with Ba 2+ lowered the temperature at which NO x conversion began. The highest performance occurred for La 0.7 Ba 0.3 FeO 3 , whereas adding more barium to La 0.6 Ba 0.4 FeO 3 reduced activity.