温度对共沉淀法制备LaMnAl11O19催化剂的影响

Coprecipitation method was employed to prepare LaMnAl11O19 catalyst for methane combustion. Sodium carbonate was used as precipitator in the process. The influences of precipitation temperature on the structure and property of the catalysts were investigated by XRD、SEM、BET techniques. The optimal calcination temperature of the catalysts was determined. The results show that the crystal phase and activity for methane combustion are greatly affected by precipitation temperature, and hexaaluminates with high activity were formed when catalysts were calcinated at 1200 ℃ for 4h. Typically at the precipitation temperature of 90 ℃, the specific surface area of the catalyst is about 19.6 m2/g, and the lightoff temperature (T 10% for methane combustion is 432℃ and the full conversion temperature is 712℃.