Catalytic oxidation of 1,2-dichloropropane over supported LaMnOx oxides catalysts
Résumé
LaMnO3 perovskites supported on Al2O3, TiO2, YSZ and CeO2 were prospectively synthesized by the in situ citrate sol-gel method. The physicochemical properties of these prepared materials were characterized by XRD, N-2 sorption, H-2-TPR, O-2-TPD and NH3-TPD. The catalytic performances of these materials were evaluated in the catalytic oxidation of 1,2-dichloropropane (1,2-DCP), which was selected as a model reaction for chlorinated volatile organic compounds (CVOCs) abatement. It was shown that LaMnO3 perovskite structures were successfully formed over TiO2 and YSZ (LMO/TiO2 and LMO/YSZ), while just characteristic diffraction peaks assigned to oxide supports were observed over Al2O3 and CeO2 supported catalysts (LMO/Al2O3 and LMO/CeO2). The perovskites supported on TiO2 and YSZ presented higher catalytic activities than the perovskite alone. However, catalyst LMO/CeO2 exhibited an optimum catalytic behavior with high catalytic stability and durability for the oxidation of 1,2-DCP. Both the concentration of surface adsorbed oxygen species and the surface acidity were considered as the main factors responsible for the catalytic performances of these materials. Moreover, it was observed that oxygen mobility originated from the interaction of LaMnO3 and/or LaMnOx phases with oxide supports could be an additional parameter influencing the catalytic performance. (C) 2016 Elsevier B.V. All rights reserved.