本研究主要探討如何利用超臨界流體的輔助下，一步合成鈀/石墨稀觸媒材料，並針對屬於多溴聯苯醚環境有機汙染物之4-溴聯苯醚（4-Brominated Diphenyl Ether, 4-PBDE）進行降解。本實驗主要利用二維石墨烯片（Graphene flakes, GF）做為觸媒載體，利用超臨界氫氣（scH2）將鈀金屬奈米修飾於二維石墨烯片上，以製備鈀/石墨烯奈米金屬觸媒，並於超臨界二氧化碳（scCO2）輔助下，對於4-PBDE進行降解反應。本研究首先將GF與六氟乙丙醯酮鈀試劑於甲醇溶液混和後，當通入超臨界氫氣後反應5分鐘時，即可於二維石墨烯片上形成鈀金屬奈米粒子，並經由洩壓過程，得到鈀/石墨烯奈米金屬觸媒（PdGF）。該複合觸媒的相關物化特性，則利用XRD、STEM、SEM、ICP-MS及XPS進行分析。於最佳化的合成條件時，鈀金屬奈米粒子於PdGF複合觸媒的平均大小約為6.45±1.37 nm，並以零價與二價鈀氧化態均勻分布在GF載體上。當以PdGF觸媒對於4-PBDE進行降解時，於通入2900 psi二氧化碳與150 psi的氫氣混和氣體，並且反應溫度為75℃條件下時，實驗結果顯示可以於30分鐘下可將100 ppm之4-PBDE，全數降解為毒性較低的產物二苯醚與環己醇和環己烷。當進行觸媒重複性降解4-PBDE之測試時，實驗結果顯示當使用超臨界氬氣與超臨界氫氣各別活化PdGF時，該觸媒對於4-PBDE進行第五次降解仍保有78%的活性。並且添加4-PBDE於海砂以及土壤時，可於不接觸海砂或土壤等真實樣品情況下，除了可以有效萃取其中之4-PBDE外，並於1個小時內並完全降解。基於上述實驗結果，本研究發展了一種新穎的降解4-PBDE於真實環境固態樣品之策略，可應用於淨化受持久性有機物汙染之固態環境樣品之可能性。

This study mainly focuses on the one-step synthesis of palladium/graphene (PdGF) catalyst materials using supercritical fluid for the degradation of 4-brominated diphenyl ether (4-PBDE). PdGF catalyst was prepared by supercritical reduction of palladium(II) hexafluoroacetylacetonate onto graphene nanosheet by introducing supercritical hydrogen fluid for 5 minutes. Relevant physicochemical properties of the PdGF composite were analyzed by XRD, STEM, ICP-MS, SEM and XPS. Under optimized conditions, the average size of Pd nanoparticles on the PdGF composite catalyst is about 6.45±1.37 nm, and also evenly distributed with both zero- and di-valent palladium oxidation states. In the presence of PdGF catalyst, result demonstrated that 100 ppm of 4-PBDE can be completely degraded following the debromination/ hydrogenation pathways into less toxic products, including diphenyl ether, cyclohexanol, and cyclohexane in 30 minutes. While activating by supercritical argon and supercritical hydrogen fluids, PdGF catalyst also possesses a reasonable activity of 78% for 4-PBDE degradation. In the case of spiked with 4-PBDE sea sand and soil samples, we found that the 4-PBDE was degraded entirely within 1 hour of reaction time. Based on the above experimental results, this study provides a novel strategy for degrading 4-PBDE in real environmental solid samples, which has the potential to purify solid environmental samples contaminated by persistent organic compounds.

一、 緒論 1
1.1 研究動機 1
二、文獻討論 3
2.1持久性有機汙染物 3
2.1.1持久性有機汙染物的性質 3
2.1.2多溴聯苯醚（PBDEs） 5
2.1.2.1多溴聯苯醚毒性之研究 6
2.1.2.2多溴聯苯醚 PBDEs 在環境中之分布 7
2.1.2.3降解多溴聯苯醚的處理方式 8
2.2超臨界流體 9
2.2.1超臨界流體性質 9
2.2.2超臨界流體種類 10
2.2.3 超臨界流體合成金屬奈米粒子 11
2.2.4超臨界流體二氧化碳參與催化反應的優點 13
2.3石墨烯 （Graphene） 14
2.3.1石墨烯的特性 14
2.4鈀金屬/石墨烯材料之應用 16
2.5研究目的 18
三、研究方法 19
3.1儀器藥品 19
3.1.1藥品 19
3.2實驗設備及儀器 20
3.2.1超臨界流體裝置 20
3.2.2 場發射穿透式電子顯微鏡(液態樣品與軟物質) 21
3.2.3 熱場發射掃描式電子顯微鏡 21
3.2.4 D2 PHASER粉末X 光繞射儀 21
3.2.5 三重四極桿氣相層析質譜儀 21
3.2.6 電化學分析儀 21
3.3實驗方法 22
3.3.1超臨界合成 22
3.3.1.1超臨界合成鈀/石墨烯金屬觸媒 22
3.3.1.2水相合成鈀/石墨烯金屬觸媒 22
3.3.2超臨界脫溴加氫反應 22
3.3.2.1 4-PBDE 回收率測試 22
3.3.2.2 4-PBDE加入金屬觸媒不通入氫氣 23
3.3.2.3超臨界二氧化碳加氫氣與金屬觸媒降解4-PBDE 23
3.3.2.4超臨界二氧化碳清洗真實樣品土壤 23
3.3.2.5利用超臨界二氧化碳萃取土壤中 4-PBDE 回收率測試 24
3.3.2.6超臨界二氧化碳加氫氣與金屬觸媒降解真實樣品土壤中 4-PBDE 24
3.3.3氣相層析質譜儀參數 25
3.3.3.1氣相層析儀分析參數 25
四、結果與討論 27
4.1利用超臨界合成之鈀/石墨烯觸媒之特性 27
4.2利用鈀/石墨烯觸媒材料降解4-PBDE 36
4.2.1 4-PBDE降解機制 36
4.2.2 利用之超臨界流體裝置進行4-PBDE萃取 38
4.2.3 利用GC-MS定量分析4-PBDE與其降解產物 40
4.2.4 利用鈀/石墨烯材料於超臨界流體下降解4-PBDE 42
4.2.4.1不同含量之Pd降解4-PBDE 42
4.2.4.2不同合成溫度之PdGF/2.5對於降解4-PBDE的影響 44
4.2.4.3鈀/石墨烯觸媒利用scH2不同合成時間對降解4-PBDE的影響 46
4.2.4.4 利用PdGF對於4-PBDE降解溫度優化之探討 48
4.2.4.5 4-PBDE降解時間探討 50
4.2.4.6降解4-PBDE時所添加不同氫氣壓力之影響 52
4.3製備與分析不同鈀/石墨烯觸媒材料之性質以及降解4-PBDE之效果 54
4.4鈀/石墨烯觸媒降解4-PBDE重複性測試 56
4.4.1超臨界氬氣和超臨界氣氣重新活化金屬觸媒 56
4.4.1.1超臨界氬氣活化之重複性測試 56
4.4.1.2超臨界氫氣活化之重複性測試 58
4.4.1.3先通超臨界氬氣後通超臨界氫氣活化之重複性測試 59
4.4.1.4觸媒降解後及活化後之STEM分析 60
4.4.1.5觸媒降解後及活化後之SEM/EDX元素分析 62
4.4.1.6觸媒降解後及活化後之XPS分析 64
4.4.1.7 觸媒降解後及活化後之電化學阻抗光譜之分析 66
4.5降解真實樣品中4-PBDE之測試 68
4.5.1降解海沙中環境汙染物4-PBDE 68
4.5.2降解土壤中環境汙染物4-PBDE 70
4.5.3探討不同反應時間降解土壤中環境汙染物4-PBDE 71
4.5.4探討降解土壤中不同濃度之環境汙染物4-PBDE 72
五、結論 73
六、參考文獻 75

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