Hβ沸石催化合成2,6-二异丙基萘

Synthesis of 2,6-diisopropylnaphthalene over zeolite Hβ catalyst

采用高压釜对Hβ沸石催化剂的萘异丙基化催化反应性能进行评价。系统考察了溶剂用量、异丙醇与萘的物质的量比、Hβ沸石用量、反应温度及反应时间等因素对异丙基化反应的影响,优化了反应条件。实验结果表明,合成2,6-二异丙基萘(2,6-DIPN)适宜的反应条件是:溶剂十氢萘用量25 mL.(0.05 mol-萘)-1,n(异丙醇)∶n(萘)=2.5∶1,催化剂用量15%,反应温度270℃,反应时间6 h,此时萘的转化率达66.41%,DIPN及2,6-DIPN的收率分别达到18.72%和3.41%,同时2,6-DIPN和2,7-DIPN的比值达到1.56。覆硅改性Hβ沸石,在基本不改变孔道性能的前提下,有效钝化其外表面酸性位,从而改善其催化萘异丙基化反应的综合性能。硅油沉积量为0.4 mL.g-1时,萘转化率81.21%,2,6-DIPN收率7.60%,2,6-DIPN与2,7-DIPN的比值保持在1.52的较高水平。

Isopropylation of naphthalene with isopropyl alcohol to 2, 6-diisopropylna-phthalene （2, 6- DIPN） over Hβ zeolite was studied. Effects of solvent dosage, n（ isopropyl alcohol） ： n（ naphthalene）, catalyst dosage, reaction temperature and reaction time were investigated. Hβ zeolite exhibited higher conversion and selectivity for isopropylation of naphthalene under mild reaction condition. Optimal reaction condition was obtained as follows ： solvent dosage 25 mL, n （naphthalene） = 0.05 mol, n （ isopropyl alcohol）： n（naphthalene） = 2.5： 1, catalyst dosage 15%, reaction temperature 270 ℃, reaction time 6 h. Naphthalene conversion of 66. 41%, diisopropylnaphthalene （DIPN） yield of 18. 72% and 2, 6-diisopropylnaphthalene （2, 6-DIPN）yield of 3.41% were obtained under the optimal reaction condition, with the ratio between 2, 6-DIPN and 2, 7-DIPN of as high as 1.56. Framework structure of HI3 zeolite after silicon-modification was basically unchanged, but surface area and number of acid sites decreased, which enhanced its properties for isopropylation of naphthalene. Under dosage of silicon oil 0.4 mL · g^-1 Hβ, naphthalene conversion of 81.21% ,2, 6-DIPN yield 7.60%, and 2, 6-DIPN to 2, 7- DIPN ratio of as high as 1.52 were attained.