Crystal structure stability and catalytic activity of magnetoplumbite (MP) catalyst doped with Mn and Mg

LaMgxMn1-xAl11O19 catalysts with Magnetoplumbite (MP) structure were prepared by the reverse microemulsion method, where x values were varied in the range of 0-1. The effects of Mn and Mg introductions on crystalline phase compositions, texture and activities of the catalysts were investigated. The catalysts were characterized by XRD, N-2 adsorption, TEM, H-2-TPR, TG-DTA, etc. The results showed that LaMg0.5Mn0.5Al11O19 catalyst had high surface area (40.1 m(2) g(-1)/1200 degrees C 5 h); LaMg0.5Mn0.5Al11O19 catalyst exhibited the high activity for CH4 combustion (T-10 = 470 degrees C, T-90 = 690 degrees C). It was believed that a synergetic effect of Mg and Mn is beneficial to enhance the stability and catalytic activity of the crystals. (c) 2007 Elsevier B.V. All rights reserved.