ZSM-5/SAPO-34复合分子筛的合成及甲醇制烯烃催化性能

Preparation of ZSM-5/SAPO-34 composite zeolite and its catalytic performance for methanol-to-olefins reaction

将预处理的ZSM-5分子筛加入到SAPO-34分子筛的合成混合物中,合成了ZSM-5/SAPO-34双微孔复合分子筛。采用XRD、SEM、FT-IR、NH3-TPD对其结构及物化性能进行了表征,并以甲醇制烯烃(MTO)反应对其催化性能进行了评价。结果表明,以该复合分子筛为催化剂时,甲醇转化率可以长时间维持近100%水平,其催化稳定性远远高于SAPO-34分子筛;与ZSM-5分子筛和相应的机械混合样品相比,具有更高的乙烯、丙烯选择性。因此,ZSM-5/SAPO-34复合分子筛有可能是一种适宜的MTO反应催化剂。

A ZSM-5/SAPO-34 bimicroporous structure composite was synthesized in-situ by adding pretreated ZSM-5 powder into the synthesis gel of SAPO-34 zeolite, and characterized by SEM, XRD, FT-IR and NH3-TPD. The catalytic performance of the composite zeolite for methanol-to-olefins（MTO） reaction was investigated, and results showed that, compared with the SAPO-34 zeolite, the composite zeolite had much better catalytic activity stability and lifetime, keeping near 100 percent methanol conversion for a long time, and, compared with the mechanical mixture of ZSM-5 and SAPO-34, the composite zeolite had better selectivity of light olefins. Hence, ZSM-5/SAPO-34 composite was likely to be a suitable catalyst in MTO reaction.