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

Abstract

<span>In this study, La</span><span lang="PT-BR">–</span><span>Mn</span><span lang="PT-BR">–</span><span>Cr perovskite-type catalysts were synthesized as </span><span>LaMnO₃,</span><span>LaCrO₃, and LaMn_0.5Cr_0.5O₃</span><span>by a microwave-assisted gel-combustion method. They were then calcined at 600^oC for 5h</span><span> in air</span><span>. X-ray diffraction (XRD) </span><span>analysis indicated that the crystalline perovskite phase is the dominant phase formed in all the synthesized samples. </span><span>The scanning electron microscopy (SEM)</span><span> analysis showed that the perovskites have a full spongy and porous structure. </span><span>The specific surface area (BET)</span><span> analysis showed a specific surface area of about 12.4</span><span lang="PT-BR">-</span><span>26.8 m²/g, and the highest specific surface area belonged to the LaMn_0.5Cr_0.5O₃ perovskite. Moreover, the highest oxygen mobility revealed by the </span><span>temperature-programmed desorption of oxygen (O₂</span><span lang="PT-BR">–</span><span>TPD) </span><span>analysis was related to </span><span>the LaMn_0.5Cr_0.5O₃sample</span><span>. </span><span>The catalytic activity of the synthesized perovskites in catalytic oxidation of 1000 ppm trichloroethylene (TCE) in air was investigated at different temperatures</span><span>. The substituted perovskite (</span><span>LaMn_0.5Cr_0.5O₃) with the highest BET specific surface area and the highest oxygen mobility </span><span>yielded the best catalytic performance among the probed perovskites. </span>