应用密度泛函理论和量子力学与分子力学联合的ONIOM2方法对含Ti的MFI分子筛(TS-1)中Ti4+离子在三种不同骨架落位上所表现的Lewis酸性进行了理论研究. 利用碱性探针分子(CO, NH3, 乙腈和吡啶)在骨架Ti活性中心的吸附作用,对吸附络合物的几何结构和吸附能进行了计算,并通过自然键轨道(NBO)分析考察了吸附络合物的电子结构. 结果表明,骨架Ti在T12位表现出明显的Lewis酸性,对NH3分子有较强的吸附作用. NBO分析表明,骨架Ti活性中心的Lewis酸性是由于 Ti - O 键的空σ反键轨道接受碱性探针分子提供的孤对电子;NH3分子吸附导致Ti4+离子由近正四面体中心对称变为五配位的三角双锥对称.
参考文献
| [1] | 夏清华;王公慰;应慕良;曹国英,郑禄彬 .[J].催化学报,1994,15(02):109. |
| [2] | Behrens P;Felsche J;Nlenmann W .[J].Catalysis Today,1991,8(04):479. |
| [3] | 程时标;吴巍;金泽明;闵恩泽 .[J].催化学报,1998,19(04):293. |
| [4] | Notari B .[J].Catalysis Today,1993,18(02):163. |
| [5] | 王祥生 .[J].精细化工,1996,13(01):30. |
| [6] | Hadjiivanov K;Reddy B M;Knzinger H .[J].Applied Catalysis A:General,1999,188(1-2):355. |
| [7] | 陈国辉.不同来源的钛硅沸石的孔结构、酸性和催化性能[J].高等学校化学学报,1996(09):1454. |
| [8] | 夏清华;郑禄彬;王公慰;应慕良 .[J].石油化工,1995,24(08):534. |
| [9] | Auroux A;Gervasini A;Jorda E;Tuel A .[J].Studies in Surface Science and Catalysis,1994,84:653. |
| [10] | Busca G;Saussey H;Saur O;Lavalley J C Lorenzelli V .[J].Applied Catalysis,1985,14:245. |
| [11] | Zhuang J Q;Ma D;Yan Z M;Deng F Liu X M Han X W Bao X H Liu X W Guo X W Wang X Sh .[J].Journal of Catalysis,2004,221(02):670. |
| [12] | Manoilova O V;Dakka J;Sheldon R A;Tsyganenko A A .[J].Studies in Surface Science and Catalysis,1995,94:163. |
| [13] | J nchen J;Vorbeck G;Stach H;Parltiz B Van Hoof J H C .[J].Studies in Surface Science and Catalysis,1995,94:108. |
| [14] | Astoeino E;Peri J B;Willey R J;Busca G .[J].Journal of Catalysis,1995,157(02):482. |
| [15] | Deo G;Turek A M;Wachs I E;Huybrechts D R C Jacobs P A .[J].Zeolites,1993,13(05):365. |
| [16] | Sasidharan M;Kumar R .[J].Catalysis Letters,1996,38(3-4):251. |
| [17] | Sasidharan M;Raju S V N;Srinivasan K V;Paul V Kumar R.[J].Chemical Communications,1996(02):129. |
| [18] | van der Waal JC.;Tan K.;van Bekkum H.;Kunkeler PJ. .Zeolite titanium beta - A selective catalyst for the gas-phase Meerwein-Ponndorf-Verley, and Oppenauer reactions[J].Journal of Catalysis,1998(1):74-83. |
| [19] | Sastre G;Corma A .[J].Chemical Physics Letters,1999,302(5-6):447. |
| [20] | Van Koningveld H;Jansen J D;Van Bekkum H J .[J].Zeolites,1990,10:236. |
| [21] | Alvarado-Swaisgood A E;Barr M K;Hay P J;Redondo A .[J].Journal of Physical Chemistry,1991,95(24):10031. |
| [22] | Deka R C;Nasluzov V A;Shor E A I;Shor A M Vayssilov G N Rosch N .[J].Journal of Physical Chemistry B,2005,109(51):24304. |
| [23] | Marra G L;Artioli G;Fitch A N;Milanesio M Lamberti C .[J].Microporous and Mesoporous Materials,2000,40(1-3):85. |
| [24] | Lamberti C.;Zecchina A.;Artioli G.;Marra G.;Spano G.;Bordiga S. .Ti location in the MFI framework of Ti-silicalite-1: A neutron powder diffraction study[J].Journal of the American Chemical Society,2001(10):2204-2212. |
| [25] | Hijar C A;Jacubinas R M;Eckert J;Henson N J Hay P J Ott K C .[J].Journal of Physical Chemistry B,2000,104(51):12157. |
| [26] | Henry P F;Weller M T;Wilson C C .[J].Journal of Physical Chemistry B,2001,105(31):7452. |
| [27] | Njo S L;van Koningsveld H;van de Graaf B .[J].Journal of Physical Chemistry B,1997,101(48):10065. |
| [28] | Shor E A I;Shor A M;Nasluzov V A;Vayssilov G N Rosch N .[J].Journal of Chemical Theory and Computation,2005,1(03):459. |
| [29] | Limtrakul J;Inntam C;Truong T N .[J].Journal of Molecular Catalysis A:Chemical,2004,207(02):139. |
| [30] | Maseras F.;Morokuma K. .IMOMM - A NEW INTEGRATED AB INITIO PLUS MOLECULAR MECHANICS GEOMETRY OPTIMIZATION SCHEME OF EQUILIBRIUM STRUCTURES AND TRANSITION STATES[J].Journal of Computational Chemistry: Organic, Inorganic, Physical, Biological,1995(9):1170-1179. |
| [31] | Humbel S.;Morokuma K.;Sieber S. .THE IMOMO METHOD - INTEGRATION OF DIFFERENT LEVELS OF MOLECULAR ORBITAL APPROXIMATIONS FOR GEOMETRY OPTIMIZATION OF LARGE SYSTEMS - TEST FOR N-BUTANE CONFORMATION AND S(N)2 REACTION - RCL+CL-[J].The Journal of Chemical Physics,1996(5):1959-1967. |
| [32] | Solans-Monfort X;Bertran J;Branchadell V;Sodupe M .[J].Journal of Physical Chemistry B,2002,106(39):10220. |
| [33] | Pabchanda S;Pantu P;Limtrakul J .Hydrolysis of methoxide species and regeneration of active site in Fe-ZSM-5 catalyst by the ONIOM method[J].Journal of molecular catalysis, A. Chemical,2005(1/2):103-110. |
| [34] | Nurbosyn U.Zhanpeisov;Masakazu Anpo .Hydrogen Bonding versus Coordination of Adsorbate Molecules on Ti-Silicalites:A Density Functional Theory Study[J].Journal of the American Chemical Society,2004(30):9439-9444. |
| [35] | Frisch M J;Trucks G W;Schlegel H B;Scuseria G E,Robb M A.Gaussian 03.Revision C.02[M].Wallingford:Gaussian,Inc,2004 |
上一张
下一张
上一张
下一张
计量
- 下载量()
- 访问量()
文章评分
- 您的评分：
-
10%
-
20%
-
30%
-
40%
-
50%