Hβ沸石催化剂催化α-甲基萘的异构化反应

Isomerization of α-Methylnaphthalene on HP Zeolite Catalysts

研究了α-甲基萘在HZSM-5,HY,HUSY,Hβ沸石催化剂上的异构化反应。发现催化剂活性和选择性与沸石的孔道结构和表面酸性相关,Hβ沸石催化剂能有效地抑制双分子歧化副反应。在相同的反应条件下,Hβ沸石催化剂表现出较高的反应活性和β-甲基萘选择性。同时,采用Hβ沸石作为α-甲基萘异构化催化剂,考察了催化剂制备及异构化反应条件。结果表明,当反应温度低于300℃时,主要发生异构化反应;在较高温度下,歧化反应成为主要反应。在较佳反应条件下,α-甲基萘的转化率为70.0296,异构化产物β-甲基萘的选择性在97％以上。

Isomerization of a - methylnaphthalene on HUSY, HY, HZSM - 5 and Hβzeolite catalysts was studied. Catalytic activity of zeolites was correlated to their surface acid - strength and pore structure. The undesired disproportionation was strongly suppressed on Hβ zeolite, presumably due to transition state of shapeselectivity. At same reaction conditions, Hβzeolite exhibited better activity and higher selectivity to 2 -methylnaphthalene. Preparation method of zeolite, influence of dosage of catalyst, reaction temperature and reaction time were investigated. At lower temperature (below 300 ℃) , isomerization was the only reaction; however,with increase in temperature, disproportionation became a main reaction. Suitable reaction conditions were selected; under which, conversion of a - methylnaphthalene was 70.02 % , selectivity of β -methylnaphthalene was over 97 % .