吳紀聖臺灣大學：化學工程學研究所吳怡亭Wu, Yi-TingYi-TingWu2007-11-262018-06-282007-11-262018-06-282007http://ntur.lib.ntu.edu.tw//handle/246246/52314氮氧化物(NOx)為一般人們所熟知的空氣污染物，本實驗欲探討 在低溫下(100℃以下)，以光驅動的方式是否也能達到選擇性還原的 目的，運用原位傅立葉轉換紅外線光譜儀(In situ Fourier Transform Infrared Spectroscopy)，可以觀察反應中間體，進而瞭解反應機制。 本實驗用熱水解法（thermal-hydrolysis method）製備光觸媒純二氧化 鈦和1wt%白金負載的二氧化鈦。光觸媒催化反應是以紫外光為光 源。本實驗觀察在25、50 及100℃下，甲烷與一氧化氮同時吸附在 二氧化鈦與1wt%白金負載的二氧化鈦上。照光後，大部分的甲烷在 光催化反應中形成了甲酸及二氧化碳。一氧化氮在吸附時變成二氧化 氮、雙牙基亞硝酸和單牙基硝酸，照光後雙牙基亞硝酸消失，取而代 之的是雙牙基硝酸、單牙基硝酸以及異氰酸鹽NCO 的產生，許多文 獻視其為選擇性吸附之中間產物，又加上本研究也觀察到NH2，故推 測在本實驗中，照光可以促進部分一氧化氮催化變成氮氣，進而達到 低溫選擇性還原的目的。NOx is a well-known air pollutant. We propose to remediate NOx by photo catalytic reduction at low temperature (<100℃). In situ FTIR was used to observe reaction intermediates and to explore possible mechanisms. The thermal-hydrolysis method was used to prepare TiO2 and 1wt% Pt-TiO2 photocatalysts. UV light was used as light source. The reactants, CH4 and NO, are adsorbed on the photocatalyst (TiO2 or 1wt% Pt-TiO2), the reaction was performed at three temperatures (25, 50 and 100℃). Under light irradiation, most of the CH4 is converted to formic acid and CO2. When NO is adsorbed on the photocatalyst, it becomes NO2, bidentate nitrites and monodentate nitrate. After light irradiation, bidentate nitrite disappears, while bidentate nitrate, monodentate nitrate and isocyanate are generated. Literatures suggest that NCO is the main intermediate in the selective catalytic reduction (SCR) process. In addition, NH2 was also observed in this experiment. Finally it is concluded that NO can be reduced to N2 by low temperature SCR under light irradiation.摘要...................................................................................................................... I Abstract ...............................................................................................................II 目錄................................................................................................................... III 圖目錄................................................................................................................ V 表目錄..............................................................................................................XII 第一章 緒論................................................................................................... 1 第二章 文獻回顧........................................................................................... 2 2-1 研究背景相關文獻回顧......................................................................... 2 2-1-1 二氧化鈦簡介................................................................................. 2 2-1-2 一氧化氮選擇性還原相關文獻回顧........................................... 6 2-2 紅外線偵測相關文獻回顧................................................................... 10 2-2-1 二氧化鈦光催化反應與其紅外線偵測實驗............................... 10 2-2-2 甲烷氧化反應與其偵測圖譜....................................................... 14 2-2-3 一氧化氮選擇性還原反應與其相關偵測圖譜............................ 16 第三章 實驗部分........................................................................................... 18 3-1 化學藥品與器材資料........................................................................... 18 3-1-1 藥品................................................................................................ 18 3-1-2 器材................................................................................................ 19 3-2 觸媒製備............................................................................................... 20 3-3 觸媒特性檢測....................................................................................... 22 3-3-1 X 光繞射儀.................................................................................... 22 3-3-2 紫外線-可見光光譜儀................................................................... 25 3-3-3 傅立葉轉換紅外線光譜儀............................................................ 27 IV 3-4 原位傅利葉轉換紅外線偵測光反應系統........................................... 30 3-4-1 反應系統........................................................................................ 30 3-4-2 光反應器........................................................................................ 31 3-4-3 原位一氧化氮與甲烷之光催化反應............................................ 33 第四章 實驗結果........................................................................................... 35 4-1 原位傅立葉轉換紅外線光譜儀偵測光催化....................................... 35 4-1-1 前處理............................................................................................ 35 4-1-2 觸媒TiO2 進行甲烷吸附與照光作用.......................................... 41 4-1-3 觸媒TiO2 進行一氧化氮吸附與照光作用.................................. 43 4-1-4 觸媒Pt-TiO2 進行一氧化氮吸附與照光作用............................. 46 4-1-5 觸媒TiO2 在25℃進行一氧化氮和甲烷的吸附與照光作用..... 51 4-1-5-1 先通入甲烷再通入一氧化氮後照光.................................... 51 4-1-5-2 先通入一氧化氮再通入甲烷後照光.................................... 54 4-1-5-3 同時通入一氧化氮與甲烷後照光........................................ 57 4-1-6 觸媒Pt-TiO2 在25℃進行一氧化氮和甲烷的吸附與照光作用60 4-1-7 觸媒TiO2 在50℃進行一氧化氮和甲烷的吸附與照光作用..... 66 4-1-8 觸媒Pt-TiO2 在50℃進行一氧化氮和甲烷的吸附與照光作用69 4-1-9 觸媒TiO2 在100℃進行一氧化氮和甲烷的吸附與照光作用... 73 4-1-10 觸媒Pt-TiO2 在100℃進行一氧化氮和甲烷的吸附與照光作用 .................................................................................................................. 76 4-1-11 觸媒TiO2 在100℃進行一氧化氮和甲烷的吸附（不照光）. 81 4-2 X 光繞射儀............................................................................................ 82 4-3 紫外線-可見光光譜儀........................................................................... 83 第五章 結果討論........................................................................................... 84 5-1 不同溫度下一氧化氮與甲烷吸附在同一觸媒後照光比較............... 84 5-2 同溫度下一氧化氮與甲烷吸附在不同觸媒後照光比較................... 87 5-3 一氧化氮與甲烷光催化之可能機制推導............................................ 92 第六章 結論..................................................................................................... 96 第七章 參考文獻............................................................................................. 97 附錄................................................................................................................. 1072105414 bytesapplication/pdfen-US一氧化氮甲烷選擇性還原原位傅立葉轉換紅外線光譜NOCH4SCRin situ FTIRthesishttp://ntur.lib.ntu.edu.tw/bitstream/246246/52314/1/ntu-96-R94524009-1.pdf