不同硅源合成ZSM-5分子筛及其MTP反应催化性能

Effect of silica soures on synthesis of ZSM-5 and their catalytic properties for MTP reaction

分别以硅溶胶和粗孔硅胶为硅源合成ZSM-5分子筛样品A和B,用XRD、SEM、XRF、NH3-TPD方法对合成的样品进行了表征,并考察了用盐酸和硝酸铵分别进行离子交换活化对其甲醇制丙烯(MTP)催化反应性能的影响。结果表明,样品A和B粒度分布均匀,粒径在500nm以下,样品B晶粒略小,且酸性较强;样品A以硝酸铵交换可保持催化剂活性,而对于酸性较强的样品B,盐酸交换可提高丙烯选择性,降低烷烃生成量。

ZSM-5 sample A and B were synthesized by using liquid silica sol and coarse silica gel as silica source, respectively,and characterized by XRD, SEM, XRF and NH3-TPD. The effects of activating the samples by ion exchange with hydrochloric acid and ammonium nitrate, respectively, on their catalytic performances in methanol to propylene（MTP） reaction were investigated.Results showed that both of sample A and B had uniform particle size distribution and their particle sizes were all below 500 nm.Compared with A, sample B had slightly smaller particle size and stronger acidity; activating sample A by ion exchange with ammonium nitrate could keep its high catalytic activity in MTP reaction; and treating the stronger acidic sample B by ion exchange with hydrochloric acid could improve propylene selectivity and lower alkane generation.