微波合成與鑑定三度空間SBA-16及奈米尺度中孔分子篩

Microwave synthesis and characterization of three-dimensional SBA-16 and nano-scale nanoporous molecular sieves

吳莉莉(Li-Li Wu)

指導教授 ： 鄭吉豐

中原大學/理學院/化學研究所/碩士(2004年)

https://doi.org/10.6840/cycu200400450

摘要

本研究主要探討以微波能( Microwave energy )合成三度空間SBA-16及奈米尺度中孔分子篩兩種材料，藉由微波能快速、高效率達到均勻加熱的特性，探討微波條件對材料結構的影響並找出以微波水熱法合成材料的最適條件。
立方排列中孔分子篩SBA-16經微波原位攪拌( in-situ stirring ) 合成，幫助反應能快速達平衡，其產物的晶格參數、孔洞大小和孔洞總體積比未攪拌微波合成法的產物要高，改變微波合成的溫度和時間將對材料的結構和型態造成影響。我們在微波溫度110 ℃下微波攪拌所合成出產物，其表面積可達850 m2 / g，孔洞大小為6.7 nm。從X-ray繞射圖和狹窄的孔洞分佈圖中顯示有傑出的中孔分子篩結構性質。
以微波水熱法合成二氧化矽、矽酸鋁、矽酸鎵奈米尺度中孔分子篩研究中，發現在微波溫度180 ℃下微波5至30分鐘即可得到具有孔洞結構的奈米尺度中孔分子篩，其產顆粒大小約20至100 nm，表面積約600～1000 m2 /g，孔洞總體積約1.0～2.0 cm3 / g，孔徑分佈非常狹窄，從X-ray繞射圖、氮氣等溫吸/脫附和穿透式電子顯微鏡得知，其產物孔洞體積與顆粒大小分別受到微波溫度與微波時間的變化而有顯著的影響。其中矽酸鋁分子篩顆粒大小約為20-30 nm，且有百分之八十以上的鋁以四配位存在於骨架中，以異丙苯( cumene )作活性測試其轉化率約為一般材料的兩倍，說明其觸媒應用性重要。

關鍵字

中孔分子篩

並列摘要

In this study, we have applied the microwave technique to synthesize three-dimensional SBA-16 and nano-scale nanoporous molecular sieves. The technique offers many distinct advantages over conventional synthesis such as rapid heating, dissolving and well mixing.
Microwave hydrothermal techniques with in-situ stirring not only speed up the crystallization of SBA-16 but also synthesize products with larger cubic unit cell, pore size and total pore volume as compared to that without stirring. In-situ stirring series of SBA-16 with good XRD patterns and narrow pore size distribution show their superior quality of cubic mesoporous structure. Products crystallized at 383K have surface area and pore size about 850 m2/g and 6.7 nm, respectively. We have also studies the influence of microwave irradiation reaction time and temperature on the SBA-16 structure and morphology.
A series of nano-scale silicate, aluminosilicate and gallosilicate mesoporous molecular sieves can be prepared by microwave hydrothermal techniques for the radiation from 5 to 30 minutes. These nano-scale nanoporous materials own high surface area (600～1000 m2/g ), pore valume (1.0～2.0 m3/g), narrow pore size distribution and nanoparticle size between 20 and 100 nm, which were characterized by XRD patterns, N2 adsorption/desorption isotherms, and TEM pore image. Microwave irradiation temperature and time play an important role on these properties.

並列關鍵字

mesoporous

參考文獻

1. McBain, J. W. In The Sorption of Gases and Vapours by Solids : Rutledge and Sons, London, 1932 ; ch. 5.

7. Lin, Y. C.; Chen, S. H.; Itri, R. J. Phys. : Condens. Matels. 1996, 8, 12169

9. Chen, C.; Li, H.; Daris, M. E. Microporous Matels., 1993, 2, 17.

11. Yao, Y. F.; Zhang, M. S.; Yang, Y. S. Aata Phys-Chim Sin. 2001, 1117.

13. Komarneni, S.; Olanrewaju, J.; Newalkar, L. B. J. Phys. Chem. B 2001, 105, 8356.