硅区尺寸对SAPO-34分子筛稳定性和酸性的影响  

Effect of Si Island Size on Stability and Acidity of SAPO-34 Molecular Sieve

作　　者：武真羽 刘红艳[2] 刘平[3] 章日光[1] 凌丽霞[1] 王宝俊[1] 

机构地区：[1]太原理工大学煤科学与技术教育部和山西省重点实验室,太原硕士生030024 [2]山西大同大学化学与环境工程学院,山西大同博士副教授037009 [3]中国科学院山西煤炭化学研究所,太原博士副研究员030001

出　　处：《煤炭转化》2017年第3期34-43,共10页Coal Conversion

基　　金：国家自然科学基金资助项目(21276171,21506120和21576178);山西省留学回国人员科研项目(2016-104)

摘　　要：构建了SAPO-34分子筛中不同尺寸的硅区Si_n(n=5,8,9,11,12,13,14),并运用色散力修正的密度泛函理论(DFT-D)方法研究了SAPO-34分子筛中不同尺寸硅区形成的难易,以及所形成硅区对SAPO-34分子筛的稳定性和酸性的影响.计算结果表明:在SAPO-34分子筛中,含Si_5和Si_9的硅区容易形成.硅区尺寸越大,SAPO-34分子筛的结构越稳定,酸性越强.同时给出了预测含有不同硅区的分子筛中各酸性位强弱次序的规则.SAPO-34 molecular sieve with different sizes of Si islands Sin（n=5, 8, 9, 11, 12, 13, 14） was constructed and investigated using dispersion-corrected density functional theory method in order to study the formation of Si islands, and the effects on the stability and acidity of SAPO-34 molecular sieve were studied. It indicates that the Si islands including Sis and Si9 are easy to form in SAPO-34 molecular sieve. In addition, the larger the Si island is, the more stable the structure is and the more acidity the Bronsted sites are. The rule is proposed to judge the acidic strength in SAPO-34 molecular sieve with different sizes of Si islands.

关 键 词：SAPO-34分子筛 BRΦNSTED酸 硅区 稳定性 酸性 密度泛函理论 

分 类 号：TQ530[化学工程—煤化学工程] TQ018