水热处理时间对甲醇制丙烯工业催化剂性质及反应性能的影响

摘要

采用X射线衍射(XRD)、N2吸附-脱附和NH3程序升温脱附(NH3-TPD)等方法对经过不同水热处理时间处理后的甲醇制丙烯(MTP)ZSM-5分子筛催化剂的晶相、孔结构和酸性进行了表征,并考察了不同水热处理时间对该工业催化剂的MTP催化性能的影响.结果表明,经过水热处理,催化剂的晶相结构未发生明显改变,引入的介孔特征随着处理时间的延长而越发明显,酸强度变化不明显,但弱酸量与总酸量均出现了下降.性能评价表明,随着水热处理时间的延长,催化剂单程寿命明显缩短,产物中丙烯的质量分数略有增加,水热处理72h时丙烯平均选择性较高,为44.45%.%X-ray diffraction(XRD),N2adsorption-desorption and NH3temperature programmed desorption(NH3-TPD)methods were used to characterize the crystal phase,pore structure and acidity of the methanol-to-propylene(MTP)ZSM-5 zeolite catalysts treated with different hydrothermal treatments.The effects of different hydrothermal treatment time on the catalytic performance of the industrial catalyst for MTP were investigated.The results showed that the crystal structure of the catalyst did not change significantly after hydrothermal treatment.The mesopore characteristics introduced were more obvious with the extension of treatment time,but the acid strength did not change obviously.However,the amount of weak acid and total acid decreased.The performance evaluation showed that with the prolongation of hydrothermal treatment,the life time of one-way catalyst was obviously shortened,the propylene content in the product slightly increased,and the average selectivity of propylene was 44.45% after hydrothermal treatment for 72 h.