表面改質中孔洞二氧化矽的二氧化碳吸附

The Adsorption of CO2 on Amine Modified Mesoporous Silica

張舫嫕(Fang-Yi Chang)

指導教授 ： 趙桂蓉

國立清華大學/理學院/化學系/碩士(2008年)

https://doi.org/10.6843/NTHU.2008.00235

摘要

本研究以一維孔道結構的中孔洞二氧化矽為載體，將具有氨基的改質劑，以矽烷化作用接合於其孔道壁上，並進行含氨基中孔洞二氧化矽的二氧化碳吸附。
首先以3-乙氧基矽烷基丙胺(mono-amine) 作表面改質，不同孔徑大小的圓柱狀孔道結構之中孔洞二氧化矽MCM-41，SBA-15及擴孔後的SBA-15為載體。然後使用三種氨改質劑 (3-乙氧基矽烷基丙胺，mono-amine；N-三甲氧基矽烷基乙二胺，di-amine；N-三甲氧基矽烷基二乙基三胺，tri-amine)，調整改質的反應條件，進行中孔洞二氧化矽 SBA-15 的表面修飾。在鑑定分析方面，分別以粉末X光繞射、等溫氮氣吸附等方法分析改質後樣品的結構及孔洞變化，並進行其二氧化碳的吸附。由元素分析、熱重分析法偵測含氨基中孔洞二氧化矽樣品的氮含量及熱穩定性，且以紅外光譜偵測其吸附二氧化碳後，所形成的carbamate 或 alkylammonium carbonate / bicarbonate等物種，及這些物種於120 oC脫附二氧化碳的變化情形；推導出固體上氨基吸附二氧化碳的反應機制，及水對二氧化碳吸附的影響。並由熱重-質譜實驗得知120 oC是脫附二氧化碳的合適溫度。

關鍵字

中孔洞二氧化矽 ； 二氧化碳 ； 氨

並列摘要

In this thesis, mesoporous silica of one-dimensional channel structure loaded with amine was used for CO2 adsorption.
Cylindric mesoporous silica MCM-41, SBA-15 or pore-expanded SBA-15 silicas were used as supports for grafting 3-aminopropyl-triethoxysilane (mono-amine), N-[3-(trimethoxysilyl) propyl]ethylene diamine (di-amine), or N-[3-(trimethoxysilyl)propyl] diethylene triamine (tri-amine). The pore structure of amine-functionalized silicas was characterized by powder X-ray diffraction and N2 adsorption /desorption at 77 K, and their carbon dioxide adsorption capacity was also examined. Fuethermore, the nitrogen content and thermal stabilities of amine-functionalized SBA-15 were analyzed by elemental and thermal gravimetric methods. The reaction mechanism of CO2 adsorption on amine-grafted SBA-15 have been proposed in the presence and absence of water vapor, and confirmed by Infrared spectroscopy. The captured CO2 could be almost completely removed from amine-SBA-15 at 120 oC detected by TGA-MS.

並列關鍵字

Mesoporous Silica ； CO2 ； amine

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