同晶置换改性FAU分子筛结构及吸附性能的密度泛函理论研究  

Theoretical Studies on the Structure and Adsorption Properties of Isomorphously Substituted FAU Zeolite

作　　者：杨丙星[1,2] 叶丽萍[1,2] 顾慧劼 徐华胜[2,3] 罗勇[1,2] 李会英[4] YANG Bingxing YE Liping GU Huijie XU Huasheng LUO Yong LI Huiying(State Key Laboratory of Polyolefins and Catalysis, Shanghai 200062, China Shanghai Research Institute of Chemical Industry, Shanghai 200062, China Shanghai Luqtiang New Materials Co., Ltd., Shanghai 201608, China Research Institute of Applied Catalysis, Shanghai Institute of Technology, Shanghai 201418, China)

机构地区：[1]聚烯烃催化技术与高性能材料国家重点实验室,上海200062 [2]上海化工研究院,上海200062 [3]上海绿强新材料有限公司,上海201608 [4]上海应用技术学院应用催化研究所,上海201418

出　　处：《高等学校化学学报》2016年第11期2018-2024,共7页Chemical Journal of Chinese Universities

基　　金：上海张江国家自主创新示范区专项发展资金重点项目(批准号:201505-PT-B108-004)资助~~

摘　　要：采用密度泛函理论(DFT)方法,考察了八面沸石(FAU)型分子筛β笼孔道结构内含氧化合物(甲醇、二甲醚、丙醛)的吸附,并进一步计算研究了Zn,Ca同晶置换改性的作用机理.研究结果表明,β笼孔道结构内,Al原子为甲醇、二甲醚和丙醛的吸附活性位,Si原子无吸附活性.Zn,Ca掺杂的β笼结构内,正2价的Zn和Ca掺杂替换正3价的Al,导致邻近的Si原子位置形成缺电子空穴,增强了甲醇、二甲醚和丙醛的吸附,而杂原子Zn和Ca本身并没有吸附活性.The adsorption of oxygenated chemicals（ methanol,dimethyl ether,propionaldehyde） in channel structure of FAU type zeolite β cage,as well as the modification mechanism of Zn / Ca isomorphous substitution were investigated by means of density functional theory（ DFT） calculations. The results indicate that methanol,dimethyl ether and propionaldehyde can chemisorb at the top site of the Al atom,while they can barely adsorb at the Si atom. For Zn-/ Ca-doped β cage,Al3＋was substituted by Zn2＋/ Ca2＋,a hole was formed on the adjacent Si atom due to the loss of one electron,therefore the adsorption of methanol,dimethyl ether and propionaldehyde were enhanced. However,the dopant atom itself doesn＇t serve as adsorption site.

关 键 词：密度泛函理论 FAU分子筛 掺杂 吸附 

分 类 号：O641[理学—物理化学]