摘要
以六亚甲基亚胺(HMI)为模板剂,通过改变合成条件制备了MCM-22分子筛,并考察了合成条件对MCM-22结晶情况的影响。凝胶配比和晶化条件对分子筛合成的影响很大:当n(SiO2):n(Al2O3)-25~50、n(HMI):n(SiO2)-0.20~0.40、n(OH^-)。n(SiO2)=0.10~0.18时,150℃下晶化48~108h可得到纯的MCM-22分子筛。经NH4NO3。交换所得HMCM-22分子筛催化剂对重芳烃加氢脱烷基反应具有良好的催化性能,在反应温度为460℃、压力为3.0MPa、空速为3.62h叫及氢烃体积比为1600的条件下,其重芳烃转化率介于HZSM-5和Hβ之间,但苯、甲苯、二甲苯(BTX)总选择性最高,可达到83.6%。
MCM-22 zeolites were synthesized using hexamethyleneimide (HMI) as the structuredirecting agent, and the effect of the gel composition and crystallization conditions on the synthesis was investigated in detail. With the gel composition of n(SiO2) : n(Al2O3)=25-50, n(HMI) : n(SiO2)=- 0.20-0.40 and n(OH^-) : n(SiO2)=0.10-0.18, pure MCM-22 was prepared after crystallization at 150 ℃ for 48-108 h. After being ion exchanged with NH4NO3, the result that HMCM-22 show desirable catalytic properties for the hydrodealkylation of heavy aromatics, which gave a C9^+ conversion between those of HZSM-5 and Hi3, but exhibited the highest selectivity of 83.6% at 460 ℃, 3.0 MPa, 3.62 h^-1 and the H2 to hydrocarbon volumn ratio of 1 600.
出处
《华东理工大学学报(自然科学版)》
EI
CAS
CSCD
北大核心
2008年第4期472-476,共5页
Journal of East China University of Science and Technology
关键词
MCM-22
水热合成
重芳烃
脱烷基
MCM-22
hydrothermal synthesis
heavy aromatics
hydrodealkylation