- 學位論文
鈀/石墨烯複合觸媒在戴奧辛類環境汙染物之整治-碳氧斷鍵降解
Palladium/Graphene Catalyst for Remediation of Environmental Contaminants— Carbon-Oxygen Bond Cleavage of Dioxins
摘要
根據斯德哥爾摩公約內容，戴奧辛因具有毒性高、在自然環境中不容易分解、會長期累積在環境以及生物體中等特性，故被列為持久性有機汙染物之一。持久性有機汙染物的處理直到現今仍為被關注的環保議題，如何降低其濃度、毒性或是如何使其降解為小分子，一直都是科學家有興趣的課題。 近年來，戴奧辛的處理方法之相關研究，諸如球磨法、光降解或高溫裂解等方法，雖可以成功降低戴奧辛之毒性，但仍有時間或是溫度上的限制。故尚有許多學者繼續研究相關議題，以期能找到較簡單之處理方法。 而本研究使用奈米鈀/石墨烯（Palladium/ Graphene；簡稱Pd/G）複合觸媒來尋找能降解此持久性有機汙染物─戴奧辛的最佳反應條件。研究中利用在超臨界二氧化碳的環境下，改變不同條件降解2-氯戴奧辛，發現當觸媒中鈀金屬所含的比例越高，反應後2-氯戴奧辛降解為小分子的效果越好；而改變溫度、氫氣量及反應時間後，發現在115 ℃、20 atm的氫氣量和75 atm的二氧化碳混合後，反應1小時後，可將2-氯戴奧辛降解為小分子的效果最好。最後研究中也改以正己烷溶劑當介質做反應及改以類戴奧辛結構的物質當反應物進行反應，得到的降解效果皆良好。未來可望應用至多氯聯苯、多氯呋喃等其他持久性有機汙染物上，且除了可處理氣相汙染物之外，液相中之汙染物也可望去除或是降低其毒性。
並列摘要
According to the Stockholm Convention, dioxins is a class of substances which is hard to break down in the natural environment, with high toxicity. It will accumulate in the environment and the body, thus is listed as one of the persistent organic pollutants. Question on how to reduce persistent organic pollutants's concentration and toxicity, or how to degrade it into small molecules is still a key topic of scientists who have been concerned about environmental issues. In recent years, related research of dioxins, such as ball milling, photodegradation or pyrolysis and other methods, can successfully reduce the toxicity of dioxins, but they are limited by time or temperature. Researchers continue to strive discover simpler and more efficient methods to remediate dioxins. In this study, we use palladium/ graphene (Pd/G) catalyst to degrade 2-chloro-dibenzo-p-dioxin in supercritical carbon dioxide. When the ratio of metal Pd in catalyst increases, degradation into small molecules is enhanced. After varying the temperature, the amount of hydrogen gas, and the reaction time, it was found that 115°C, 1 hour reaction time, and 20 atm hydrogen gas mix with 75 atm carbon dioxide, produce the best results. The hydrodechlorination of 2-chloro-dibenzo-p-dioxin is achieved and C-O bond is broken. The end products are mainly dodecahydrodibenzo [b,e][1,4]dioxin, 2-(cyclohexenyloxy)cyclohexanol and cyclohexane.
參考文獻
延伸閱讀
- 張健威、胡哲嘉（2018）。氧化石墨烯複合鈦酸鍶光觸媒製備與其對有機汙染物廢水分解應用。鑛冶：中國鑛冶工程學會會刊，62(2)，62-65。https://doi.org/10.30069/MM.201806_62(2).0005
- 李育誠（2014）。石墨烯/氧代氮代苯并環己烷/環氧樹脂/碳纖維積層板複合材料機械性質與疲勞特性之研究〔碩士論文，國立清華大學〕。華藝線上圖書館。https://www.airitilibrary.com/Article/Detail?DocID=U0016-2912201413501002
- Chen, T. C. (2021). 開發硫脲交聯自組裝還原氧化石墨烯球從回收電子廢棄物的廢水中選擇性吸附/還原黃金 [master's thesis, National Taiwan University]. Airiti Library. https://doi.org/10.6342/NTU202100854
- Wang, G. S. (2017). Novel polyurethane dispersant for disperse graphene for flexible conductive film uses [master's thesis, National Taiwan University]. Airiti Library. https://doi.org/10.6342/NTU201701768
- Li, D. W., Luo, L., Lv, P. F., Wang, Q. Q., Lu, K. Y., Wei, A. F., & Wei, Q. F. (2016). Synthesis of Polydopamine Functionalized Reduced Graphene Oxide-Palladium Nanocomposite for Laccase Based Biosensor. Bioinorganic Chemistry and Applications, 2016(), 96-105. https://doi.org/10.1155/2016/5360361