The investigation of sorption performance of mesoporous SBA-15 and its metal modified composites

SBA-15以及金屬改質SBA-15複合材料之吸附研究

張凱評(Kai-ping Chang)

指導教授 ： 王竹方

國立清華大學/原子科學院/生醫工程與環境科學系/碩士(2009年)

https://doi.org/10.6843/NTHU.2009.00346

摘要

本研究目的為研究中孔洞材料SBA-15對水中汙染物的吸附特性，將Ti與Ca分別改質於SBA-15基材上，以增加傳統SBA-15純矽材料的應用範圍和能力。研究過程中，首先以共沉澱方法合成新穎的TiSBA-15材料，結合SBA-15的孔洞特性以及Ti的光催化特性，使TiSBA-15同時具備吸附及光催化降解污染物的能力；其次，將Ca離子以含浸法披覆於SBA-15基材上，經由鍛燒形成CaO/SBA-15複合材料，使SBA-15具備吸附CO2的能力。本實驗使用XRD、BET、SEM/EDX、TEM與ICP-MS等儀器鑑定SBA-15以及其複合材料的基本特性。在性能測試方面，以陽離子型分子、陰離子型分子和中性分子進行SBA-15的吸附研究；以亞甲基藍染料進行TiSBA-15的吸附與光催化再生能力的實驗；最後探討CaO/SBA-15在高溫環境下吸附CO2的可行性。實驗結果顯示，SBA-15對於陽離子型分子有明顯的吸附能力，對於陰離子型分子和中性分子則否。SBA-15的吸附行為可用Langmuir、Freundlich和pseudo-second order模式進行模擬。亞甲基藍染料可有效的被TiSBA-15吸附，且經由適當的光催化程序，可以證明TiSBA-15具有同時催化與礦化污染物；以及再生TiSBA-15的功能。高溫吸附CO2實驗證明，CaO/SBA-15在700℃有最佳的CO2捕捉能力，在910℃能將CO2脫附，其最大吸附容量可達43wt%。經20次吸脫附循環實驗後之CO2捕捉效率仍可維持85%以上，顯示CaO/SBA-15為一極具潛力的高溫CO2捕捉複合材料。

關鍵字

SBA-15 ； TiSBA-15 ； CaO/SBA-15

並列摘要

The purpose of this study is to investigate the adsorptive properties of pollutants on SBA-15 in solution. Titanium (Ti) and Calcium (Ca) were modified on SBA-15 supports in order to improve the applications of traditional SBA-15 materials. A novel Ti-containing SBA-15 (TiSBA-15) material using co-precipitation method combines the adsorptive capability of mesoporous SBA-15 and photocatalytic ability of Ti. This combination makes TiSBA-15 a potential material to adsorb the pollutant and then degrade it photocatalytically. CaO/SBA-15 composite was synthesized by impregnation method using calcium acetate as the calcium precursors and then calcined to form CaO on the surface of SBA-15. The modification of Ca on SBA-15 leads into the ability to absorb CO2.
All prepared materials were characterized by powder X-ray diffraction patterns (XRD), nitrogen sorption isotherms techniques, scanning electron microscopy (SEM), energy dispersive spectroscopy (EDX), transmission electron microscopy (TEM), and inductively coupled plasma-mass spectroscopy (ICP-MS). In terms of adsorption properties, the performance was examined by the adsorption of dyes on prepared materials. It is concluded that SBA-15 exhibits an excellent adsorptive capability of cationic molecules but almost no adsorption of anionic and neutral molecules. Langmuir model, Freundlich model, and pseudo-second-order kinetics were well-fitted in the simulation of the adsorption behavior of dyes on prepared materials. The photodegradation of MB and TOC analysis on solid composites were used to evaluate the catalytical performance of TiSBA-15. An adsorption and photocatalysis process cycle test was used to estimate the regeneration performance of TiSBA-15. The results indicate that TiSBA-15 can be an effective material to reduce organic pollutants in solution. The CO2 adsorption performance on CaO/SBA-15 was evaluated by TG analysis. The composite is considered as a potential high temperature CO2 adsorbent with an over 85% uptake ability after 20 cyclic runs.

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