金屬有機骨架之改質與應用

Surface Modification and Applications of Metal-Organic Frameworks

邱浩哲(Hao-Che Chiu)

指導教授 ： 康敦彥

國立臺灣大學/工學院/化學工程學研究所/碩士(2016年)

https://doi.org/10.6342/NTU201602364

摘要

本研究嘗試以金屬有機骨架為主體，於其外包覆二種或二種以上的微孔洞材料(金屬有機骨架、沸石、非結晶性二氧化矽)，以合成高效能、高穩定性的核殼式吸附劑，並對材料進行多種檢測，包含酸性環境中的穩定性、水熱環境中的穩定性、水氣吸附性及離子吸附性，從檢測結果挑選適當的材料組合做為核殼式材料。將吸附性良好的材料做為核，於其外以另一種穩定的材料做為殼將核包覆住，藉由殼的保護增加核的穩定性，達到延長吸附材壽命的效果。
在水氣吸脫附的應用方面，我們選用吸附效果最佳，但水氣吸脫附循環不穩定的FeBTC做為核的材料，於其外分別以ZIF-7、ZIF-8、SiO2包覆，根據合成手法不同，共合成出了6種核殼式材料，雖然做成核殼式材料後，會因外層材料的水氣吸附率不如FeBTC，且增加水氣進入FeBTC孔道中的質傳阻力，使得整體水氣吸附率降低，但整體而言，穩定性皆有上升，而其中又以外層為ZIF-7進行三次生長的效果最好，不僅穩定性十分良好，水氣吸附率降低的情況也在可容許的範圍之內。
離子吸附的應用方面，我們選擇常見於電子面板廠廢液中的貴重金屬離子：銦離子，做為探討的主軸，核材的選擇為ZIF-8，因其吸附效果最好，不過ZIF-8在酸性環境中不穩定，而工業上含有銦離子的廢液為酸液，所以選用酸穩定性良好的SiO2做為殼材。雖然目前尚未能用SiO2完整的包覆住ZIF-8，導致酸穩定性還是不佳，但預計未來發展出能完整包覆ZIF-8的實驗方法後，穩定性定會有所提升。

關鍵字

金屬有機骨架 ； 沸石 ； 核殼式材料 ； 水氣吸脫附 ； 離子吸附

並列摘要

This work is aimed at enhancing the sorption performance of metal-organic frameworks (MOFs) by coating another porous material (a different MOF, zeolite, or amorphous silicon oxide) to create novel core-shell materials. A number of properties, including the acidic resistance, hydrothermal stability, water sorption capacity, and ion sorption capacity, were investigated to determine the appropriate “core” material and “shell” materials. To design high-performance sorbents, materials with high sorption capacity would serve as “core”, and those with high stability would serve as “shell”.

For water vapor adsorption, FeBTC with high sorption capacity but poor cyclic stability was chosen as the “core” material. ZIF-7, ZIF-8, and amorphous SiO2 were deposited on FeBTC respectively as the “shell” material. 6 core-shell materials were synthesized under various conditions. In general the core-shell materials have lower water vapor sorption capacity at the first adsorption cycle in comparison to pristine FeBTC. However, the cyclic adsorption stability has been improved through the creation of core-shell materails.

For ionic sorption application, we discussed the sorption of indium ion because it is a common waste of electronic panel factory. ZIF-8 was chosen as the core material due to its high indium sorption capacity. ZIF-8 has low acid resistance, but the indium solution is usually acidic. We attempt to deposit materials with high acid resistance on ZIF-8, such as amorphous silica. Although the ZIF-8@silica did not show an improvement of acidic stability, we believed that it was due to the low coverage of the silica on ZIF-8.

並列關鍵字

Metal-organic frameworks ； zeolite ； core-shell ； water vapor adsorption ； ionic adsorption

參考文獻

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