超微細錫改質二氧化鈰擔載銅觸媒於不同氫氧濃度下一氧化碳選擇氧化研究

Selective CO Oxidation under Different Hydrogen-oxygen Concentrations by Ultra Fine Cu/Sn-Doped Ceria Catalysts

林裕傑(Yu-Chieh Lin)

指導教授 ： 王振熙

義守大學/理工學院/化學工程學系暨生物技術與化學工程研究所/碩士(2016年)

摘要

本研究以逆微胞微乳化法製備超微細錫改質奈米二氧化鈰擔體，使用含浸法將5wt%的CuO担載到含錫的二氧化鈰上，鍛燒製成觸媒，藉由CO轉化率及選擇率在不同氫氧濃度的情況下觀察此觸媒之活性。使用微乳化法摻雜不同比例的錫，最佳摻雜比例為10 mole%，當操作溫度為60℃時，CO轉化率已達50%，操作溫度到達90℃時，CO轉化率也已達100%，CO選擇率也維持在100%。當改變氫氧濃度比例，氧氣比例增加轉化率有明顯的提高，但選擇率也相對下降。而溫度超過100℃時，因為CO消耗完而使H2與O2反應，進而產生水氣，導致選擇率下降。此外我們觀察在120℃下，CO跟H2競爭的情形，結果顯示CO競爭力高於H2，觸媒對CO有較高的選擇率，代表觸媒對CO有較高的選擇性且低溫時較不耗氫。使用比表面積測定(BET)分析觸媒，可驗證活性測試結果。

關鍵字

逆微胞微乳化 ； 一氧化碳選擇性氧化 ； 氧化錫摻雜二氧化鈰

並列摘要

Copper oxide impregnated on tin-doped ceria prepared by reverse microemulsion was used as catalysts for the selective CO oxidationin under different hydrogen oxygen concentration environment. Therefore, reverse microemulsion method was adopted in this study to prepare ceria of different percentages of tin-doping for the selective CO oxidation. Activity test results showed that the best activity performance was obtained by the catalyst of 10% tin-doped ceria, which displays a CO conversion of 50% at 60℃ and almost 100% at 90℃ while still achieving high CO selectivity of almost 100% due to little hydrogen consumption. The influences of CO selectivity in different concentration of hydrogen and oxygen, once the precentage of O2 increased, the conversion rasies as well, relatively, the selectivity drops. However, exceeding 100℃ hydrogen gradually reacts with oxygen resulting in a decrease in selectivity. In addition, from the competitive oxidation tests of CO and H2 at 120℃, it has been demonstrated that CO is more easily oxidized than H2. The catalysts studied in this work can exhibit high CO selectivity and low hydrogen consumption at low temperatures. Activity results also match with those of BET surface area.

並列關鍵字

selective CO oxidation ； reverse microemulsion ； tin-doped ceria

參考文獻

44. 馬振基，"奈米材料科技原理與應用"全華科技股份有限公司(2005)

2. J.B. Wang, W.H. Shih, T.J. Huang, “Study of Sm2O3-doped CeO2/Al2O3-supported copper catalyst for CO oxidation, ” Applied Catalysis A: General 203, 191-199. (2000)

3. J.B. Wang, D.H. Tsai, T.-J. Huang, “Synergistic catalysis of carbon monoxide oxidation over copper oxide supported on samaria-doped ceria,” Journal of Catalysis 208, 370-380.(2002)

7. 陳泓政，"燃料電池之甲醇重組器氫氣產生之研究"成功大學航太所

8. J. Han, I. Kim and K.S. Choi"Purifier-integrated methanol reformer for fuel cell vehicles"Journal of Power Sourcess, (2000)