摘要
以四丙基溴化铵为有机模板剂合成了纳米ZSM-5分子筛,将晶化合成的母液回收后,采用不同回用比例的母液部分甚至全部替代四丙基溴化铵合成纳米ZSM-5分子筛,通过XRD,SEM,NH3-TPD等方法对合成产物进行了表征。表征结果显示,母液回用比例50%时合成的纳米ZSM-5分子筛的晶相结构和酸性与无母液回用时合成的纳米ZSM-5分子筛近似。将合成的纳米ZSM-5分子筛制成催化剂,用于苯烷基化和甲苯择形歧化反应。实验结果表明,相比大晶粒ZSM-5分子筛,纳米ZSM-5分子筛制备的催化剂用于苯烷基化反应时,苯转化率和二甲苯选择性明显提高;用于甲苯择形歧化反应时,甲苯转化率和苯选择性提高接近1倍,二甲苯选择性提高1倍以上。
Nano ZSM-5 zeolite was synthesized with tetrapropylammonium bromide（TPABr） as organic template,and then the synthesizing mother solution was recovered and used partly or even totally in the synthesis of the nano ZSM-5 zeolites to replace TPABr. The products were characterized by means of XRD,SEM and NH3-TPD. It was found that the nano ZSM-5 zeolite synthesized with 50% of the mother solution had similar crystal phase structure and acidity to the nano ZSM-5 zeolite synthesized with 100% of TPABr template. The catalysts prepared from the nano ZSM-5 zeolites were used in the benzene alkylation and toluene selective disproportionation. Compared to large grain ZSM-5 zeolite catalyst,the nano ZSM-5 catalysts had the high benzene conversion and xylene selectivity in the benzene alkylation,and in the toluene selective disproportionation,both the toluene conversion and the benzene selectivity were almost doubled,and the xylene selectivity increased one time more than that on the large grain ZSM-5 zeolite catalyst.
出处
《石油化工》
CAS
CSCD
北大核心
2015年第2期163-167,共5页
Petrochemical Technology
关键词
模板剂回用
纳米ZSM-5分子筛
苯烷基化
甲苯歧化
择形催化
template recycling
nano ZSM-5 zeolite
benzene alkylation
toluene disproportionation shape-selective catalysis
