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采用常压高温水蒸汽处理的方法对丝光沸石(HM)进行改性,并用高压微型固定床反应器对改性丝光沸石进行评价,以萘的转化率和产物的选择性表征催化剂的萘异丙基化反应性能,研究了不同水蒸汽处理条件对萘异丙基化反应的影响。结果表明,提高水蒸汽处理温度和处理时间,萘的转化率降低,2,6-DIPN的选择性提高。而处理空速增加,萘的转化率和2,6-DIPN的选择性均降低。水蒸汽处理有利于减少强酸中心的数目,改变丝光沸石外表面酸性,抑制副反应的发生。适宜的水蒸汽处理条件为:温度500℃、时间1h、空速0.5h-1。HM经高温水蒸气处理后,β位及β,β位异丙基萘的选择性有所提高,同时2,6-DIPN选择性明显增大,催化剂的稳定性提高。并用NH3-TPD表征了催化剂的酸性。
Mordenite (HM) was modified by steam treatment at atmospheric pressure and high temperature, and the modified mordenite was evaluated by a high-pressure micro-fixed bed reactor. The conversion of naphthalene and the selectivity of the product were used to characterize the naphthalene isopropanol The effects of different steam treatment conditions on the isopropylation of naphthalene were studied. The results showed that the conversion of naphthalene decreased and the selectivity of 2,6-DIPN increased with the increase of steam treatment temperature and treatment time. However, with the increase of treatment airspeed, the conversion of naphthalene and the selectivity of 2,6-DIPN decreased. Steam treatment is beneficial to reduce the number of strong acid center, change the surface acidity of mordenite, inhibit the occurrence of side reactions. Suitable conditions for steam treatment: temperature 500 ℃, time 1h, space velocity 0.5h-1. After the high temperature steam treatment, the selectivity of β-position and β, β-isopropylnaphthalene increased, while the selectivity of 2,6-DIPN increased obviously and the stability of catalyst increased. NH3-TPD was used to characterize the acidity of the catalyst.