PDF (2786K)
摘要
采用水热合成法制备了系列ZSM-35分子筛,考察了有机模板剂种类、OH-/SiO2摩尔比、晶化温度和方式、焙烧温度等对ZSM-35分子筛结构和物化性质的影响。通过XRD、SEM、N2吸附脱附、NH3-TPD、吡啶-红外和固体核磁等手段对ZSM-35分子筛进行表征分析。以工业醚后碳四为原料,考察了纳米片状ZSM-35催化剂催化正丁烯骨架异构化反应性能。结果表明,当进料空速为2.0 h-1、反应压力为0.1 MPa、反应温度为310℃时,正丁烯单程转化率为45.99%,异丁烯选择性为88.50%,且催化剂具有良好的稳定性;在反应运行225 h后,依然保持催化活性。所制备的纳米片状ZSM-35催化剂的结构中拥有最多的B酸催化活性中心,促使了正丁烯骨架异构反应的发生。
Abstract
A series of ZSM-35 molecular sieves are prepared via hydrothermal method.The influences of the types of organic template,the molar ratio of OH-/SiO2,crystallization temperature and ways,and calcination temperature on the structure and physicochemical properties of ZSM-35 molecular sieves are studied.Meanwhile,ZSM-35 molecular sieves are characterized by means of XRD,SEM,N2 adsorption isotherms,NH3-TPD,pyridine IR and solid nuclear magnetic resonance.The catalytic performance of nanosheet ZSM-35 molecular sieves catalyst for skeleton isomerization of n-butene is investigated through using post C4 as raw material.Obviously,the one-way conversion of n-butene reaches 45.99% and the selectivity of isobutylene reaches 88.50% when the feed space velocity is 2.0 h-1,the reaction pressure is 0.1 MPa,and the reaction temperature is 310℃.Meanwhile,the nanosheet ZSM-35 molecular sieve catalyst possesses good stability.After experiencing 225 h of reaction,it still maintains its catalytic activity.The prepared nanosheet ZSM-35A catalyst owns the largest number of Bronsted acid active site in its structure,which stimulates n-butene skeleton isomerization.
关键词
ZSM-35分子筛
/
异构化
/
正丁烯
/
B酸位
/
纳米片状
Key words
ZSM-35 molecular sieve
/
isomerization
/
n-butene
/
B acid site
/
nanosheet
纳米片状ZSM-35分子筛的合成及在正丁烯骨架异构化反应中的催化性能研究[J].
现代化工, 2023, 43(10): 195-200,207 DOI:10.16606/j.cnki.issn0253-4320.2023.10.036