分别采用离子交换法和物理混合法制备了不同Zn含量的ZSM-5分子筛催化剂，采用X射线衍射、扫描电子显微镜、N2物理吸附、氨程序升温脱附、吡啶红外吸附光谱、紫外-可见光谱和X射线光电子能谱等技术研究了催化剂的结构、表面性质及Zn物种种类，探讨了Zn物种存在状态对乙烯芳构化反应的影响。结果表明，引入到HZSM-5中的Zn物种包括三种状态，即ZnO晶体、存在于分子筛孔道中的ZnO团簇以及Zn和分子筛质子酸中心通过固相反应生成的Zn(OH)+物种；不同的制备方法显著影响Zn物种的分布。比较了制备方法和Zn含量对ZSM-5分子筛催化剂在乙烯芳构化反应中性能的影响，发现Zn(OH)+物种是芳构化的主要活性中心，同时ZnO物种的存在有助于乙烯制芳烃反应的发生。
Zn-containing HZSM-5 zeolites with different Zn contents were prepared by ion exchange and physically mixing methods, and were characterized by X-ray diffraction, scanning electron micro-scope, N2 adsorption-desorption, NH3 temperature programmed desorption, pyridine adsorption infrared spectroscopy, ultraviolet-visible diffuse reflectance spectroscopy and X-ray photoelectron spectroscopy. Zn species introduced into HZSM-5 were identified as ZnO crystals, ZnO clusters in the zeolite channel and Zn(OH)+species formed from a solid state reaction between dispersed ZnO and the protons in the zeolite. The preparation method has a significant influence on the distribu-tion of the Zn species. The catalytic behavior of Zn-containing HZSM-5 with different Zn contents showed that the Zn(OH)+and ZnO species were responsible for aromatic formation from ethylene.
参考文献
| [1] | Liu H M;Li Y;Shen W J;Bao X H Xu Y D .[J].Catalysis Today,2004,93-95:65. |
| [2] | 艾沙·努拉洪,刘家旭,贺宁,郭洪臣.正丁烷在Au,Zn组合改性纳米HZSM-5上的催化转化[J].催化学报,2013(06):1262-1266. |
| [3] | Song, YQ;Zhu, XX;Xie, SJ;Wang, QX;Xu, LY .The effect of acidity on olefin aromatization over potassium modified ZSM-5 catalysts[J].Catalysis Letters,2004(1/2):31-36. |
| [4] | Song Y Q;Zhu X X;Xu L Y .[J].Catalysis Communications,2006,7:218. |
| [5] | Choudhary V R;Panjala D;Banerjee S;Kinage A K .[J].Microporous and Mesoporous Materials,2001,47:253. |
| [6] | Choudhary V R;Banerjee S;Panjala D .[J].Journal of Catalysis,2002,205:398. |
| [7] | Yakovlev A L;Shubin A A;Zhidomirov G M;Van Santen R A .[J].Catalysis Letters,2000,70:175. |
| [8] | Lubango LM.;Scurrell MS. .Light alkanes aromatization to BTX over Zn-ZSM-5 catalysts - Enhancements in BTX selectivity by means of a second transition metal ion[J].Applied Catalysis, A. General: An International Journal Devoted to Catalytic Science and Its Applications,2002(1/2):265-272. |
| [9] | 尹双凤,林洁,于中伟.锌含量对Zn/HZSM-5催化剂性能的影响[J].催化学报,2001(01):57-61. |
| [10] | 陈军,丁富新,张鎏,康慧敏.ZnO/HZSM-5丙烷芳构化催化剂中锌的形态表征[J].催化学报,2001(03):229-232. |
| [11] | 倪友明,孙爱明,吴小岭,胡江林,李涛,李光兴.La/Zn/HZSM-5催化剂上的甲醇芳构化研究[J].中国化学工程学报（英文版）,2011(03):439-445. |
| [12] | Xin Y B;Qi P Y;Duan X P;Lin H Q Yuan Y Z .[J].Catalysis Letters,2013,143:798. |
| [13] | 陈军,张鎏,康慧敏,丁富新.含锌HZSM-5催化剂的XPS表征与丙烷芳构化性能[J].石油学报（石油加工）,2000(05):8-13. |
| [14] | Berndt H;Lietz G;V?iter J .[J].Applied Catalysis A:General,1996,146:365. |
| [15] | Kolyagin YG;Ordomsky VV;Khimyak YZ;Rebrov AI;Fajula F;Ivanova II .Initial stages of propane activation over Zn/MFI catalyst studied by in situ NMR and IR spectroscopic techniques[J].Journal of Catalysis,2006(1):122-133. |
| [16] | Biscardi JA.;Iglesia E.;Meitzner GD. .Structure and density of active Zn species in Zn/H-ZSM5 propane aromatization catalysts[J].Journal of Catalysis,1998(1):192-202. |
| [17] | Yakerson V I;Vasina T V;Lafer L I;Sytnyk V P Dykh G L Mokhov A V Bragin O V Minachev K M .[J].Catalysis Letters,1989,3:339. |
| [18] | Li Q H;Mihailova B;Creaser D;Sterte J .[J].Microporous and Mesoporous Materials,2000,40:53. |
| [19] | Maderia F F;Tayeb K B;Pinard L;Vezin H Maury S Cadran N .[J].ApplCatal A,2012,443-444:171. |
| [20] | Ni Y M;Sun A M;Wu X L;Hai G L Hu J L Li T Li G X .[J].Microporous and Mesoporous Materials,2011,143:435. |
| [21] | El-Malki El-M;Van Santen R A;Sachtler W M H .[J].Journal of Physical Chemistry B,1999,103:4611. |
| [22] | Kolyagin YG;Ordomsky VV;Khimyak YZ;Rebrov AI;Fajula F;Ivanova II .Initial stages of propane activation over Zn/MFI catalyst studied by in situ NMR and IR spectroscopic techniques[J].Journal of Catalysis,2006(1):122-133. |
| [23] | Niu X J;Gao J;Miao Q;Dong M Wang G F Fan W B Qin Z F Wang J G .[J].Microporous and Mesoporous Materials,2014,197:252. |
| [24] | Bordiga S;Lamberti C;Ricchiardi G;Regli L Bonino F Damin A Lillerud K P Bjorgen M Zecchina A .[J].Chemistry Communications,2004,20:2300. |
| [25] | Haase M;Weller H;Henglein A .[J].Journal of Physical Chemistry,1988,92:482. |
| [26] | Liu J X;Ai Sha N L H;He N;Liu G D Liang C C Zhang X F Guo H C .[J].CHEMICAL ENGINEERING JOURNAL,2013,218:1. |
| [27] | Tholkappiyan R;Vishista K .[J].Physical B,2014,448:177. |
| [28] | Qiu P.;Rosynek MP.;Lunsford JH. .Characterization of Ga/ZSM-5 for the catalytic aromatization of dilute ethylene streams[J].Catalysis Letters,1998(1/2):37-42. |
| [29] | 毕怡,王莹利,陈欣,于政锡,许磊.不同锌盐改性的HZSM-5催化剂上甲醇芳构化反应[J].催化学报,2014(10):1740-1751. |
| [30] | Choudhary V R;Panjala D;Banerjee S .[J].Applied Catalysis A:General,2002,231:243. |
- 下载量()
- 访问量()
- 您的评分：
-
10%
-
20%
-
30%
-
40%
-
50%