本研究旨在製備銀-鉑/二氧化鈰奈米粉體以應用於催化CO氧化上。實驗中，首先以沉澱法合成顆粒狀(P-)及針狀(N-)CeO2擔體，接著，以微濕含浸法將銀、鉑和銀-鉑擔載於CeO2粉體上，製得銀/二氧化鈰、鉑/二氧化鈰及銀-鉑/二氧化鈰觸媒。文中針對擔體?燒還原條件、金屬含量及擔體晶形來加以探討，並利用TEM、BET、XRD、DRIFT、Raman、XPS及H2-TPR等技術來進行觸媒特性分析。另外，將觸媒填充於反應器中進行CO氧化反應，以探討各觸媒之催化活性。
在製備Ag/N-CeO2觸媒中，針對未含浸銀時擔體是否?燒以及含浸後之?燒還原條件來加以比較，結果發現，含浸銀後經?燒500 oC、2 h，再在300 oC下氫氣還原3 h，所得觸媒之催化活性最高。當銀擔載量在0.05%~5%之間時，隨著銀含量由0%增加至3 %時，CO轉化率明顯隨之增高，且半轉化溫度(T50)由270 oC降至50 oC；此結果與H2-TPR分析一致。此外，由Raman結果證實，銀可促進CeO2氧空缺之形成，進而增加CO之吸附量；另一方面，由於銀之電子遷移至CeO2上，使銀對氧分子之親和力增大；由銀與CeO2之協同作用(synergistic effect)造成觸媒催化CO氧化之活性提高，進一步比較擔體晶形之影響，發現當銀擔載量小(〈0.5%)時，因擔體本身即具有催化能力，故觸媒活性受擔體所主導，而N-CeO2較P-CeO2擁有較高表面能，因此Ag/N-CeO2之活性優於Ag/P-CeO2。反之，當銀擔載量大(〉 0.5 %)時，由於銀之催化主導觸媒活性，故擔體晶形之影響可忽略，兩者催化活性相當。
比較Ag/N-CeO2、Pt/N-CeO2、Ag/N-CeO2+Pt/N-CeO2及Ag-Pt/N-CeO2四種觸媒之催化活性，結果發現其 CO氧化之活性依序為Ag-Pt/N-CeO2〉Pt/N-CeO2〉Ag/N-CeO2+Pt/N-CeO2〉Ag/N-CeO2，由此結果可知Ag-Pt/N-CeO2觸媒擁有最高之催化活性，其T50由原先Pt/N-CeO2(130 oC)及Ag/N-CeO2(250 oC)大幅降低至83 oC，推測係因銀-鉑雙金屬間之電子轉移，加上金屬與擔體間之協同作用所致。

Silver and platinum nanoparticles prepared by incipient wetness impregnation were employed as catalysts for CO oxidation. The physiochemical properties of nanoparticles including shape, particle size, surface area, crystalline structure, oxygen vacancies, and reducible ability are characterized using TEM, BET, XRD, Raman spectroscopy, DRIFT, XPS, ICP-AES and H2-TPR techniques. From the experimental results, it reveals that the optimized condition for Ag/N-CeO2 catalyst prepared via one-pot calcination and then reduced at 300 oC for 3h. As comparing activities of four catalysts, i.e. Ag/N-CeO2, Pt/N-CeO2, Ag-Pt/N-CeO2 and Ag/N-CeO2+Pt/N-CeO2, it was found that the activity was in the sequence of Ag-Pt/N-CeO2 〉 Pt/N-CeO2 〉 Ag/N-CeO2+Pt/N-CeO2 〉 Ag/N-CeO2. This indicated that Ag-Pt/N-CeO2 catalyst showed the Ag-Pt bimetallic interaction and highest activity on CO oxidation. This was attributed from synergistic effect of metal-support. Due to the transfer of electrons from Ag to Pt, the Ag and Pt grains exhibited higher adsorption affinity toward oxygen and carbon monoxide, respectively, which might further promote the oxidation of CO. Furthermore, the loading of Ag and Pt can facilitate the formation of oxygen vacancies of CeO2 nanoparticles, resulting in the enhancement of CO oxidation activity.

摘要 I
Extended Abstract III
誌謝 XI
目錄 XII
表目錄 XVI
圖目錄 XVIII
第一章 緒論 1
1.1 前言 1
1.2 CO來源與毒害 2
1.3 二氧化鈰之簡介 4
1.3.1 CeO2性質 4
1.3.1.1 物理性質 4
1.3.1.2 化學性質 4
1.3.1.3 光學性質 6
1.4 金屬/二氧化鈰觸媒製備 6
1.5 以金屬/CeO2觸媒催化之CO氧化 7
1.5.1 CeO2之觸媒 7
1.5.2 金屬/ CeO2之觸媒 8
1.5.3 雙金屬/CeO2觸媒 9
1.6 研究目的及概要 10
第二章 原理 19
2.1 CO氧化反應 19
2.1.1 CeO2晶面之影響 19
2.1.2 CO吸附 19
2.1.3 O2吸附 20
2.1.4 M-CeO2間之作用力 21
2.2 CO氧化之催化機制 22
第三章 實驗步驟與方法 26
3.1 實驗藥品 26
3.1.1 藥品 26
3.1.2 氣體 26
3.2 實驗設備與儀器 27
3.2.1 實驗設備 27
3.2.2 分析儀器 27
3.3 觸媒製備 28
3.3.1 二氧化鈰奈米擔體之製備 28
3.3.1.1 恆溫沉澱法 28
3.3.1.2 非恆溫沉澱法 29
3.3.2 金屬觸媒之擔載 29
3.4 觸媒特性分析 30
3.4.1 BET分析 30
3.4.2 TPR分析 30
3.4.3 TEM/HRTEM分析 31
3.4.4 ICP-OES分析 31
3.4.5 FT-IR分析 32
3.4.6 Raman分析 32
3.4.7 XPS分析 32
3.4.8 XRD分析 32
3.5 觸媒活性測試 33
3.5.1 反應條件之選擇 33
3.5.2 CO氧化反應 34
3.5.2.1 進料氣體組成之控制 35
3.5.2.2 產物氣體組成之分析 35
第四章 Ag/CeO2觸媒製備條件之影響 47
4.1 前言 47
4.2 Ag/CeO2觸媒製程變因之影響 47
4.2.1 擔體煅燒溫度之影響 47
4.2.1.1 CO氧化反應 47
4.2.1.2 BET分析結果 48
4.2.1.3 XRD分析結果 48
4.2.2 還原製程變因之影響 48
4.2.2.1 CO氧化反應 48
4.2.3 Ag擔載量之影響 49
4.2.3.1 CO氧化反應 49
4.2.3.2 TEM分析結果 50
4.2.3.3 XRD分析結果 50
4.2.3.4 BET分析結果 51
4.2.3.5 H2-TPR分析結果 51
4.2.3.6 DRIFT分析結果 52
4.2.3.7 Raman分析結果 53
4.2.3.8 XPS分析結果 54
4.2.3.8.1 Ce3d圖譜分析 55
4.2.3.8.2 O1s圖譜分析 55
4.2.3.8.3 Ag3d圖譜分析 56
4.2.3.8.4 Ag/CeO2之電子能帶階 56
4.3 DFT模擬 56
4.4 綜合討論 57
第五章 Pt/CeO2及Ag-Pt/CeO2觸媒製備條件之影響 79
5.1 前言 79
5.2 Pt/CeO2觸媒之Pt含量對活性之影響 79
5.2.1 CO氧化反應 79
5.2.2 BET分析 79
5.2.3 XRD分析 80
5.2.4 H2-TPR分析 80
5.2.5 Raman分析 81
5.2.6 Pt/CeO2之電子能帶階 81
5.2.7 DFT模擬 82
5.3 Ag-Pt/CeO2觸媒之活性探討 82
5.3.1 CO氧化反應 83
5.3.2 XRD分析 83
5.3.3 H2-TPR分析 84
5.3.4 Raman分析 84
5.4 綜合討論 84
第六章 結論與建議 97
6.1 結論 97
6.2 建議 98
參考文獻 100

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