Preparation of LaMnO3 for catalytic combustion of vinyl chloride

Abstract

LaMnO3 was prepared by citrate sol-gel, coprecipitation, hard template, and hydrothermal methods, respectively, and its catalytic performance for the combustion of vinyl chloride was investigated. N2 adsorption-desorption, X-ray diffraction (XRD), Raman spectroscopy (Raman), O2 temperature programmed desorption (O2-TPD), H2 temperature programmed surface reaction (H2-TPR) and X-ray photoelectron spectroscopy (XPS) were used to characterize the physicochemical properties of the LaMnO3 samples. The preparation methods had obvious effects on the distribution of oxygen and manganese species on the catalyst surface. The reaction followed the suprafacial mechanism; the activity corresponded with the high amount of Mn4+ and adsorbed oxygen species. LaMnO3 prepared by the citrate sol-gel method had the best performance for vinyl chloride combustion with T90 of 182 °C. The optimal activity was attributed to the improved redox capability of Mn4+/Mn3+. More available adsorbed oxygen and Mn4+ species on the surface were mainly responsible for the remarkable enhancement of the catalytic activity.