本研究著眼於設計HZSM-5(矽/鋁比為11.5)觸媒於甲醇芳香化。第一部份的研究主題為除矽與含浸鎵於HZSM-5觸媒的協同效應探討。結果顯示，除矽法不僅能夠提高中孔隙度，降低芳香族產物的擴散阻力，還能提升布朗斯特酸的強度。此外，除矽法所製造出的中孔有利於鎵的前驅物(Ga(NO3)3 6H2O)更容易擴散進入HZSM-5孔洞內，並與布朗斯特酸形成環化脫氫(cyclodehydrogenation)的活性點。具有除矽及含浸鎵金屬的HZSM-5(Ga/AT-0.01)於500oC下產出最高的芳香族選擇率。
第二部分則透過改變不同鹼處理條件以及含浸少量的鎵(1 wt%)，製備一系列HZSM-5觸媒。結果顯示，隨著鹼處理濃度提高，鎵與布朗斯特酸接觸的量就越多，但過高的鹼處理濃度(AT-0.2)則大幅破壞了HZSM-5的結構。因此，適中鹼處理後的觸媒(Ga/AT-0.05)於500oC下具有最佳的甲醇芳香化能力。另一項重要的發現是是透過適當的鹼處理能均一化HZSM-5的微孔孔徑分佈(0.55nm)，並能在反應中促進p- 與 m-xylenes的選擇率。

In this study we focus on designing HZSM-5 (Si/Al ratio = 11.5) in methanol aromatization. The first part is to explore the synergistic effect of disilication and Ga doping in HZSM-5. Desilication not only increases mesoporisity and reduces mass transfer resistance, but also enhances Brønsted acidity. In addition, gallium precursor, (Ga(NO3)3 6H2O), is easier to diffuse into HZSM-5 cavities and contacts with Brønsted acid to form cyclodehydrogenation center compared to its pristine counterpart. Ga-doped, desilicated HZSM-5 (Ga-AT0.01) has maximum aromatics selectivity at 500℃.
The second part of this work is to synthesize Ga-doped, desilicated HZSM-5 with systematically increased alkalinity. Enhancing alkalinity in desilicatoin can improve the amounts of (GaO)+-Brønsted acid site. However, severe alkalinity can destroyed HZSM-5 structure (AT-0.2). This leads Ga/AT-0.05 to be an optimal MTA catalyst.

1. Olah, G.A., Beyond Oil and Gas: The Methanol Economy. Angewandte Chemie International Edition, 2005. 44(18): p. 2636-2639.
2. Zou, H., et al., Review of Methanol to Aromatics. Acta Petrolei Sinica, 2013. 29(3): p. 539-547.
3. Chen, N.Y., T.F. Degnan Jr., and L.R. Koenig, Liquid fuel from carbohydrates. Chemtech, 1986. 16: p. 506-511.
4. Hagen, J., Industrial Catalysis: A Practical Approach, 2nd Edition. John Wiley & Sons, Inc.,. 2006.
5. Olsbye, U., et al., Conversion of Methanol to Hydrocarbons: How Zeolite Cavity and Pore Size Controls Product Selectivity. Angewandte Chemie International Edition, 2012. 51(24): p. 5810-5831.
6. Stöcker, M., Methanol-to-hydrocarbons: catalytic materials and their behavior1. Microporous and Mesoporous Materials, 1999. 29(1–2): p. 3-48.
7. Chang, C.D., A.J. Silvestri, and R.L. Smith, Production of gasoline hydrocarbons, U.p. office, Editor. 1975.
8. Chang, C.D. and A.J. Silvestri, The conversion of methanol and other O-compounds to hydrocarbons over zeolite catalysts. Journal of Catalysis, 1977. 47(2): p. 249-259.
9. Dejaifve, P., et al., Reaction pathways for the conversion of methanol and olefins on H-ZSM-5 zeolite. Journal of Catalysis, 1980. 63(2): p. 331-345.
10. Haag, W.O., R.M. Lago, and P.G. Rodewald, Aromatics, light olefins and gasoline from methanol: Mechanistic pathways with ZSM-5 zeolite catalyst. Journal of Molecular Catalysis, 1982. 17(2–3): p. 161-169.
11. Robinson, J.G., D.I. Barnes, and A.M. Carswell, Alumina and/or silica catalysts supported on microporous glass. 1983, Google Patents.
12. Parker, L.M. and D.M. Bibby, Synthesis and some properties of two novel zeolites, KZ-1 and KZ-2. Zeolites, 1983. 3(1): p. 8-11.
13. Hoelderich, W.D., W.D.D. Mross, and M.D. Schwarzmann, Verfahren zur Herstellung von Aromaten aus Methanol und/oder Dimethylether. 1983, Google Patents.
14. Chao, K.j., et al., Temperature-programmed desorption studies on ZSM-5 zeolites. Zeolites, 1984. 4(1): p. 2-4.
15. Ceckiewicz, S., Conversion of methanol into light hydrocarbons on erionite-offretite(T) zeolite. Journal of the Chemical Society, Faraday Transactions 1: Physical Chemistry in Condensed Phases, 1984. 80(11): p. 2989-2998.
16. Itoh, H., et al., Role of acid property of various zeolites in the methanol conversion to hydrocarbons. Journal of Catalysis, 1984. 85(2): p. 521-526.
17. Xu, Y., et al., An investigation into the conversion of methanol to hydrocarbons over a SAPO-34 catalyst using magic-angle-spinning NMR and gas chromatography. Catalysis Letters, 1990. 4(3): p. 251-260.
18. Ravishankar, R., et al., Characterization and catalytic properties of zeolite MCM-22. Microporous Materials, 1995. 4(1): p. 83-93.
19. Mikkelsen, Ø. and S. Kolboe, The conversion of methanol to hydrocarbons over zeolite H-beta. Microporous and Mesoporous Materials, 1999. 29(1–2): p. 173-184.
20. Dahl, I. and S. Kolboe, On the reaction mechanism for propene formation in the MTO reaction over SAPO-34. Catalysis Letters, 1993. 20(3-4): p. 329-336.
21. Dahl, I.M. and S. Kolboe, On the Reaction Mechanism for Hydrocarbon Formation from Methanol over SAPO-34: I. Isotopic Labeling Studies of the Co-Reaction of Ethene and Methanol. Journal of Catalysis, 1994. 149(2): p. 458-464.
22. Sun, X., et al., On reaction pathways in the conversion of methanol to hydrocarbons on HZSM-5. Journal of Catalysis, 2014. 317: p. 185-197.
23. Conte, M., et al., Modified zeolite ZSM-5 for the methanol to aromatics reaction. Catalysis Science & Technology, 2012. 2(1): p. 105-112.
24. Zhang, J., et al., Increasing para-Xylene Selectivity in Making Aromatics from Methanol with a Surface-Modified Zn/P/ZSM-5 Catalyst. ACS Catalysis, 2015. 5(5): p. 2982-2988.
25. Ono, Y., Transformation of Lower Alkanes into Aromatic Hydrocarbons over ZSM-5 Zeolites. Catalysis Reviews, 1992. 34(3): p. 179-226.
26. Nowak, I., et al., Effect of H2–O2 pre-treatments on the state of gallium in Ga/H-ZSM-5 propane aromatisation catalysts. Applied Catalysis A: General, 2003. 251(1): p. 107-120.
27. Dwyer, F.G. and A.B. Schwartz, Katalysator und dessen verwendung Catalyst and its use. 1978, German Patent and Trade Mark Office.
28. W, K.W., Methanol conversion to para—xylene using a zeolite catalyst containing an oxide of boron, magnesium, phosphorus, or mixtures, in US Patent Office. 1978.
29. Ono, Y., H. Adachi, and Y. Senoda, Selective conversion of methanol into aromatic hydrocarbons over zinc-exchanged ZSM-5 zeolites. Journal of the Chemical Society, Faraday Transactions 1: Physical Chemistry in Condensed Phases, 1988. 84(4): p. 1091-1099.
30. Wang, J.-y.W., Ding-zhu; Lu, Xue-don,, and Dou, Xiu-yun, CONVERSION OF LOWER ALCOHOLS INTO AROMATICS OVER CATION-MODIFIED HZSM-5 ZEOLITES. Chinese Journal of Catalysis, 1993(14(3)): p. 234-238.
31. Ono, Y., et al., Ag-ZSM-5 as a Catalyst for Aromatization of Alkanes, Alkenes, and Methanol, in Studies in Surface Science and Catalysis, H.G.K.H.P. J. Weitkamp and W. Hölderich, Editors. 1994, Elsevier. p. 1773-1780.
32. Freeman, D., R.P.K. Wells, and G.J. Hutchings, Methanol to hydrocarbons: enhanced aromatic formation using a composite GaO-H-ZSM-5 catalyst. Chemical Communications, 2001(18): p. 1754-1755.
33. Freeman, D., R.P.K. Wells, and G.J. Hutchings, Conversion of Methanol to Hydrocarbons over Ga2O3/H-ZSM-5 and Ga2O3/WO3 Catalysts. Journal of Catalysis, 2002. 205(2): p. 358-365.
34. Barthos, R., et al., Aromatization of methanol and methylation of benzene over Mo2C/ZSM-5 catalysts. Journal of Catalysis, 2007. 247(2): p. 368-378.
35. Lopez-Sanchez, J., et al., Reactivity of Ga2O3 Clusters on Zeolite ZSM-5 for the Conversion of Methanol to Aromatics. Catalysis Letters, 2012. 142(9): p. 1049-1056.
36. Niu, X., et al., Influence of preparation method on the performance of Zn-containing HZSM-5 catalysts in methanol-to-aromatics. Microporous and Mesoporous Materials, 2014. 197: p. 252-261.
37. Chérif-Aouali, L., et al., Structural evolution of dealuminated Y zeolites during various chemical treatments. Zeolites, 1988. 8(6): p. 517-522.
38. Groen, J.C., et al., Optimal Aluminum-Assisted Mesoporosity Development in MFI Zeolites by Desilication. The Journal of Physical Chemistry B, 2004. 108(35): p. 13062-13065.
39. Groen, J.C., et al., Mechanism of Hierarchical Porosity Development in MFI Zeolites by Desilication: The Role of Aluminium as a Pore-Directing Agent. Chemistry – A European Journal, 2005. 11(17): p. 4983-4994.
40. Groen, J.C., et al., Direct Demonstration of Enhanced Diffusion in Mesoporous ZSM-5 Zeolite Obtained via Controlled Desilication. Journal of the American Chemical Society, 2007. 129(2): p. 355-360.
41. Verboekend, D. and J. Pérez-Ramírez, Desilication Mechanism Revisited: Highly Mesoporous All-Silica Zeolites Enabled Through Pore-Directing Agents. Chemistry – A European Journal, 2011. 17(4): p. 1137-1147.
42. Ogura, M., et al., Alkali-treatment technique — new method for modification of structural and acid-catalytic properties of ZSM-5 zeolites. Applied Catalysis A: General, 2001. 219(1–2): p. 33-43.
43. Groen, J.C., et al., Mesoporosity development in ZSM-5 zeolite upon optimized desilication conditions in alkaline medium. Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2004. 241(1–3): p. 53-58.
44. Lietz, G., et al., Modifications of H-ZSM-5 Catalysts by NaOH Treatment. Journal of Catalysis, 1994. 148(2): p. 562-568.
45. Bjørgen, M., et al., Methanol to gasoline over zeolite H-ZSM-5: Improved catalyst performance by treatment with NaOH. Applied Catalysis A: General, 2008. 345(1): p. 43-50.
46. Song, Y., et al., An effective method to enhance the stability on-stream of butene aromatization: Post-treatment of ZSM-5 by alkali solution of sodium hydroxide. Applied Catalysis A: General, 2006. 302(1): p. 69-77.
47. Kim, Y.H., et al., Formation of Hierarchical Pore Structures in Zn/ZSM-5 to Improve the Catalyst Stability in the Aromatization of Branched Olefins. ChemCatChem, 2012. 4(8): p. 1143-1153.
48. 陳振中, 固態核磁共振光譜學簡介. 科儀新知, 2006. 第二十八卷(第三期): p. 42-49.
49. 李珠, 感應耦合電漿質譜移技術及其材料分析上的應用. 工業材料雜誌, 2002. 181期: p. 87-93.
50. Kulkarni, S.B., et al., Studies in the synthesis of ZSM-5 zeolites. Zeolites, 1982. 2(4): p. 313-318.
51. Gil, B., et al., Desilication of ZSM-5 and ZSM-12 zeolites: Impact on textural, acidic and catalytic properties. Catalysis Today, 2010. 152(1–4): p. 24-32.
52. Thomas, J.M., Dealuminated zeolites. Journal of Molecular Catalysis, 1984. 27(1): p. 59-69.
53. Brunner, E., et al., Magic-angle-spinning NMR studies of acid sites in zeolite H-ZSM-5. Journal of Catalysis, 1991. 127(1): p. 34-41.
54. Freude, D. and J. Haase, Quadrupole Effects in Solid-State Nuclear Magnetic Resonance, in Special Applications, H. Pfeifer and P. Barker, Editors. 1993, Springer Berlin Heidelberg: Berlin, Heidelberg. p. 1-90.
55. Perez-Ramirez, J., et al., Hierarchical zeolites: enhanced utilisation of microporous crystals in catalysis by advances in materials design. Chemical Society Reviews, 2008. 37(11): p. 2530-2542.
56. Playford, H.Y., et al., Characterization of Structural Disorder in γ-Ga2O3. The Journal of Physical Chemistry C, 2014. 118(29): p. 16188-16198.
57. Bayense, C.R., et al., Determination of gallium in H(Ga)ZSM5 zeolites by gallium-71 MAS NMR spectroscopy. The Journal of Physical Chemistry, 1992. 96(2): p. 775-782.
58. Groen, J.C., J.A. Moulijn, and J. Pérez-Ramírez, Decoupling mesoporosity formation and acidity modification in ZSM-5 zeolites by sequential desilication–dealumination. Microporous and Mesoporous Materials, 2005. 87(2): p. 153-161.
59. Holm, M.S., et al., Assessing the acid properties of desilicated ZSM-5 by FTIR using CO and 2,4,6-trimethylpyridine (collidine) as molecular probes. Applied Catalysis A: General, 2009. 356(1): p. 23-30.
60. Yakerson, V.I., et al., The properties of zinc and gallium containing pentasils — The catalysts for the aromatization of lower alkanes. Catalysis Letters, 1989. 3(4): p. 339-345.
61. Xiao, H., et al., A highly efficient Ga/ZSM-5 catalyst prepared by formic acid impregnation and in situ treatment for propane aromatization. Catalysis Science & Technology, 2015. 5(8): p. 4081-4090.
62. Thommes, M., S. Mitchell, and J. Pérez-Ramírez, Surface and Pore Structure Assessment of Hierarchical MFI Zeolites by Advanced Water and Argon Sorption Studies. The Journal of Physical Chemistry C, 2012. 116(35): p. 18816-18823.
63. Derouane, E.G., et al., Thermodynamic and mechanistic studies of initial stages in propane aromatisation over Ga-modified H-ZSM-5 catalysts. Journal of Molecular Catalysis, 1994. 86(1–3): p. 371-400.
64. Yu, L., et al., Transformation of Isobutyl Alcohol to Aromatics over Zeolite-Based Catalysts. ACS Catalysis, 2012. 2(6): p. 1203-1210.
65. Schulz, H., “Coking” of zeolites during methanol conversion: Basic reactions of the MTO-, MTP- and MTG processes. Catalysis Today, 2010. 154(3–4): p. 183-194.
66. Ohayon, D., et al., Methods for pore size engineering in ZSM-5 zeolite. Applied Catalysis A: General, 2001. 217(1–2): p. 241-251.
67. Lai, P.-C., et al., Methanol aromatization over Ga-doped desilicated HZSM-5. RSC Advances, 2016. 6(71): p. 67361-67371.
68. Magnoux, P. and M. Guisnet, Coking, ageing and regeneration of zeolites. Applied Catalysis, 1988. 38(2): p. 341-352.