摘要
在高浓度体系下,以粗孔硅胶和偏铝酸钠为原料,TPABr为模板剂,水热晶化法制备了ZSM-5分子筛,单釜产率23%.用不同浓度的氢氧化钠溶液对ZSM-5分子筛进行改性,采用XRD、FT-IR、SEM、NH_3-TPD、XRF、N_2物理吸附等方法对改性前后的样品进行了表征,并考察了改性后ZSM-5分子筛甲醇催化转化制丙烯(MTP)反应性能.结果表明,氢氧化钠改性未破坏分子筛的骨架结构,改性后样品的酸量、介孔孔容和BET比表面积均有增加,从而改善了催化剂的抗积碳性能和反应性能.在MTP反应中,增产丙烯的效果不明显,但表现出了更好的催化稳定性(催化剂使用寿命从85 h提升至110 h),并且有利于提高副产物汽油组分(∑C5+)的产量.
ZSM-5 zeolites were synthesized by hydrothermal crystallization method and using macroporous silica gel and sodium aluminate as raw materials and TPABr as template. The batch yield was 23%. ZSM-5 zeolite were modified by different concentration sodium hydroxide solution and characterized by XRI）, FT-IR, SEM, NH3-TPD, XRF and nitrogen adsorption, and their catalytic performance for methanol to propylene （MTP） reaction was evaluated. The results showed that the framework structure of sample was scarcely damaged after modification, the acid content, mesopores pore volume BET surface area and the performance of resistance to carbon deposition were in-creased and the catalytic cracking performances of modified ZSM-5 catalyst was improved. In MTP process, the modified samples could not increase the yield of propylene, but the modified samples exhibited noticeable enhancement in catalytic stability （the life time from 85 h to 110 h） and the yield of gasoline （ΣC5＋）.
出处
《分子催化》
EI
CAS
CSCD
北大核心
2016年第5期444-453,共10页
Journal of Molecular Catalysis(China)
基金
国家自然科学基金国际(地区)合作与交流(批准号:2015DFA40660)项目资助~~
关键词
高浓度体系
ZSM-5分子筛
碱处理
甲醇制丙烯
high concentration system
ZSM-5 zeolite
alkali-treatment
methanol to propylene
