不同金属改性HZSM-5对甲醇制丙烯(MTP)反应性能的影响

Effect of different mentals modification on catalytic performance of HZSM-5 zeolites for methanol to propylene

研究了La、Ce、Zr、Fe、K、Ca等不同金属改性的HZSM-5(n(Si O2):n(Al2O3)=150)分子筛对甲醇制丙烯(MTP)催化性能的影响。并利用X射线衍射(XRD)、N2吸附-脱附、氨-程序升温脱附(NH3-TPD)等技术对改性前后样品的结构和酸性进行了表征;并在常压、450℃和甲醇空速(WHSV)为1.25h-1的反应条件下,在连续流动固定床反应器上考察了其对甲醇制丙烯反应的催化性能。结果表明,金属改性可以有效降低HZSM-5的酸性和酸量,其中K改性的HZSM-5催化甲醇制丙烯的效果优于其他金属改性催化剂,甲醇转化率为99.5%,丙烯选择性为50.0%。

The HZSM-5 zeolite with n（SiO2）/n（A12O3） of 150 was modified by different metals La, Ce, Zr, Fe, K or Ca. The struc- ture and acidity of the modified zeolites were characterized by XRD, N2 adsorption/desorption and NH3-TPD, and their catalytic performances for methanol to propylene （MTP） reaction were tested in a continuous flow fixed-bed reactor at atmospheric pressure, 450℃ and methanol space velocity （WHSV） of 1.25h^-1. The results showed that the metal modification of HZSM-5 could reduce acid strength and acid site density which were favorable for MTP reaction, and the K-modified HZSM-5 exhibted the optimal MTP performance with a methanol conversion of 99.5% and a propylenes electivity of 50.0%.