THE PREPARETION AND CATALYTIC PROPERTIES OF La1-xSrxMnO3 (x = 0; 0.2; 0.4) PEROVSKITES in OXIDATION OF m–XYLEN

Tóm tắt

In this report, La­_1-xSr_xMnO₃ (x = 0; 0.2; 0.4) perovskite - type complex  oxides have been done by sol-gel citrate method.The formation process of La_1-xSr_xMnO₃ crystalline perovskites and characterization of these solids were examined by various physical, physico – chemical methods such as the Powder X-ray diffraction (XRD) and the Energy dispersive X-ray spectrocopy (EDXS). Results show that perovskite phases can be perfectly crystallized at the temperature of  600^oC and they have very small average particle size (14-20 nm). These perovskites exhibit a good catalytic activity in total oxidation of  m-xylene at the relatively low temperature of reaction: the oxidative conversion of m-xylene over perovskites La­_1-xSr_xMnO₃ catalysts  reaches a maximum (100%) at 300^oC temperature and be stable at this temperature . The results also indicate that partially substituting of La³⁺ with Sr²⁺ has not been effected  exactly on the oxidative conversion of  m- xylene.