Effect of preparation methods and mirror plane cation on the catalytic property of AMnAl11O19−δ (A = K, Ca) catalysts

Manganese substituted hexaaluminates were prepared either by carbonate precipitation or sol–gel method and calcined at high temperature. The structure and property of these samples were characterized by XRD, BET, SEM and TG–DTA. The series of hexaaluminates exhibited significant catalytic activity at high temperature. Upon calcination at 1200 °C K2MnAl11O19−δ retained a specific surface area of 27.6 m2/g and showed an excellent activity for methane combustion, which temperatures at 10% and 90% conversion were 490 and 670 °C, respectively.