KL催化剂上正己烷芳构化的影响.pdf

石油化工
2015年第44卷第6期
PETROCHEMICAL TECHNOLOGY
P收
KL分子筛的碱性对PKL催化剂上
正己烷芳构化的影响
宋婕2,马怀军,立军3,李伟2,曲炜,田志坚
(1.中国科学院大连化学物理研究所,辽宁大连116023;2.中国科学院大学,北京100049;
3.中国石油石油化工研究院,北京100195
摘要]采用水热晶化法合成了KL分子筛,并采用XRF,XRD,BFT,CO2-TPD等方法表征了骨架掺杂Fc原子改性和负载碱
金属盐改性对KL分子筛结构以及碱性位分布状态的影响。通过H2-TPR表征和正已烷芳构化反应,考察了负载Pt后相应催化
剂上的P颗粒状态及催化剂的芳构化性能。实验结果表明,骨架掺杂Fe原子增加了分子筛的弱碱性位数量,而负载碱金属盐
增加了分子筛的强碱性位数量;碱性位分布情况影响P在载体上的分散情况及电子状态。强碱性位数量的增多使P颗粒分散
得更加均匀且呈现出宮电子状态,明显提高了PtKL催化剂的芳构化性能,相应的Pt负载量为0.5%(w)的PtK-KL催化剂在450
℃、WHSV=3h、n(H12):n(n-C)=3的条件下,正己烷转化率达70%以上,苯选择性为85%左右。
关键词铂K催化剂;KL分子筛;正己烷;芳构化;铁摻朵
〔文章编号]1000~8144(2015)06-0683-06
中图分类号]TQ426.94
[文献标志码]A
Efiect of Basicity of K Molecular Sieves on -Heane Aromatization over P/KL Catalysts
Song Jie"", Ma Huaiji
Lijun, Li Wei", Ou Wei, Tian Zhiji
(1. Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian Liaoning 116023, China; 2. University of hinese
Academy of Sciences, Beijing 100049, China; 3. Petro China Petrochemical Research Institute, Beijing 100195, China
L Abstract KL molecular sieve was synthesized by hydrothermal crystallization method and
then K-KL and FEKL molecular sieves were prepared by the modification of KL with K and Fe
respectively. The P/K, Pt/K-KL and Pt/FEKI catalysts were prepared by impregnation method. The
molecular sieves and catalysts were characterized by means of XRF, XRD, BET, CO-TPD and H
TPR. The catalysts were used in the aromatization of n-hexane. The weak basic sites on the molecular
sieves increased with Fe doping in the hydrothermal synthesis, while the strong basic sites increase
with the introduction of K by ion exchange method, The increase of the strong basic sites led to more
uniform Pt particles and electron-rich Pt species, which improved the aromatization performances of
the Pt/KL catalyst. The conversion of n-hexane was more than 70% and the selectivity to benzene was
about 85% under the conditions of Pt/K-KL with Pt loading of 0.5%(w)as the catalyst, 450 C
WHSV 3 h and n(H): n(n-hexane )3.
I Keywords) platinum/KL catalyst; KL molecular sieves; n-hexane; aromatization; iron doping
石脑油催化重整过程是生产芳烃和高辛烷值烷烃芳构化性能。开发高性能的PtKL催化剂和新
汽油组分的重要途径。在传统的铂重整催化剂上发的轻烷烃芳构化过程是提高石脑油利用率的有效
生的主要是环烷烃的脱氢反应,石脑油中烷烃的芳措施。
构化程度有限,而碱性的PtKL催化剂具有很好的
KL分子筛是一种具有十二元环、一维孔道的
收稿日期】2014-12-29;[修改稿日期]2015-03-16。
作者简介]宋婕(1987ー),女,甘肃省金昌市人,博士生,电话0411-84379768,电邮songjie(@dicp.ac.cn。联系人:田志坚,电话
0411-84379151,电邮ianz@dicp.ac.cn