Investigation of LaMnO3 catalyst loaded on HZSM‐5 zeolite for CO catalytic oxidation

Abstract

AbstractDue to the large amounts of CO pollutant from iron ore sintering and vehicle emissions, the control of CO emission becomes more and more important for the environment. To control the emission of CO more effectively, the catalysts of LaMnO3 perovskite with HZSM‐5 zeolite as support were prepared by sol–gel method. The structure and catalytic activities of catalysts were characterized and analyzed. According to the results of X‐ray diffraction (XRD) and energy‐dispersive X‐ray spectroscopy (EDS), the LaMnO3 perovskite phase is successfully obtained in all the supported catalysts. The average particle sizes of supported catalysts are in the range of 15–38 μm. Compared with the perovskite catalysts loaded on other kinds of supports, LaMnO3 supported with HZSM‐5 has a larger specific surface area (SSA). The SSAs of supported catalysts with different loading amount are in the range of 190–300 m2/g. The HZSM‐5 support improves the catalytic activity of LaMnO3 catalyst by increasing the SSA. The activity of supported catalyst becomes higher when the loading amount increases from 20% to 60%. The catalyst with 60% perovskite loaded shows the best activity in CO catalytic oxidation. The CO conversion of 60LM/HZSM‐5 attains 50% and 90% at 172.7°C and 201.5°C, respectively. The activities of catalysts with 80% and 100% perovskite loaded decrease due to the accumulated pores formed by too much perovskite. The supported catalysts exhibit favorable activities in consecutive reaction cycles. It turns out that HZSM‐5 support is appropriate for the synthesis of active perovskite catalysts for CO oxidation.