Evaluation of LaBO3 (B=Mn, Cr, Mn0.5Cr0.5) perovskites in catalytic oxidation of trichloroethylene

Abstract

In this study, La–Mn–Cr perovskite-type catalysts were synthesized as LaMnO3,LaCrO3, and LaMn0.5Cr0.5O3 by a microwave-assisted gel-combustion method. They were then calcined at 600oC for 5h in air. X-ray diffraction (XRD) analysis indicated that the crystalline perovskite phase is the dominant phase formed in all the synthesized samples. The scanning electron microscopy (SEM) analysis showed that the perovskites have a full spongy and porous structure. The specific surface area (BET) analysis showed a specific surface area of about 12.4-26.8 m2/g, and the highest specific surface area belonged to the LaMn0.5Cr0.5O3 perovskite. Moreover, the highest oxygen mobility revealed by the temperature-programmed desorption of oxygen (O2–TPD) analysis was related to the LaMn0.5Cr0.5O3 sample. The catalytic activity of the synthesized perovskites in catalytic oxidation of 1000 ppm trichloroethylene (TCE) in air was investigated at different temperatures. The substituted perovskite (LaMn0.5Cr0.5O3) with the highest BET specific surface area and the highest oxygen mobility yielded the best catalytic performance among the probed perovskites.