Effect of Ultrasonic Treatment on the Gel Formation of MnSAPO-34 Catalysts in MTO Process

In order to synthesize the MnSAPO-34 crystal with a pure CHA structure having a uniform size and desired catalytic activity, factors having influence on the crystallization at gel preparation should be considered. In this work Diethylamine and morpholine were used as the organic templates. A perfectly homogeneous gel was obtained by ultrasonic wave treatment before hydrothermal treatment. The results showed that ultrasonic-wave treatment was effective in making particle size smaller and in narrowing the size distribution for MnSAPO-34(DEA). In addition, a uniform distribution was obtained with excelent morphology was obtained for MnSAPO-34(Mor) in compared to the one without ultrasonic treatment. Ultrasonic treated MnSAPO-34 catalysts showed similar activity and product distribution with a yield of 84% in the MTO reaction at 400℃.