Abstract: A sol-gel method was employed to prepare Mn-substituted barium hexaaluminate catalysts for methane combustion. Supercritical drying (SCD) and conventional oven drying (CD) methods were used to extract the water in the hydrogel. The effects of drying methods, as well as the incorporation of Ba, Mn, on properties of the catalysts were investigated by means of N2adsorption, TG－DTA and X-ray diffraction. The supercritical drying method could maintain a higher specific surface area of the samples and suppress the transformation into α-Al2O3 at elevated temperatures. The introduction of Mn oxides could promote the transformation into hex aluminates during calcinations. BaMnAl11O19 catalyst dried by SCD method has a specific surface area of 35.1 m2•g－1 and an activity with T10％ (temperature for 10％ methane conversion) of 500 ℃ under the condition of 0.1 MPa and 40000 h－1 GHSV.

Key words: Methane, Catalytic combustion, Supercritical drying, Ba-hexaaluminate, 　Catalyst