- 學位論文
以釤及釓修飾銅鋅觸媒進行甲醇蒸氣重組反應之研究
Promotion of Copper-Zinc Catalyst with Sm and Gd for Steam Reforming of Methanol
摘要
近年來，能源危機與溫室效應所伴隨而來的危機意識，加速各國發展替代能源，其中，氫能以潔淨無污染而受矚目，但氫能受限於氫氣運輸而難以發展。液態碳氫化合物的重組反應即可改善氫體運輸成本，又以甲醇蒸氣重組反應(steam reforming of methanol, SRM)之轉化溫度低及反應系統簡單，適時地解決問題使氫氣來源不再受限。 為了使SRM反應可以製造富氫氣氣(hydrogen-rich gas, HRG)，觸媒好壞是首要關鍵。文獻中多以銅鋅鋁催化劑進行SRM反應，本實驗則是以銅鋅鋁為基底添加不同促活劑(promoter)：釤及釓，來進行觸媒的改質，期望可以降低轉化率達95%以上的反應溫度( T95)、減少產物中一氧化碳(CO)的濃度及增加氫氣的產率(FH2)。利用X光繞射儀(XRD)來探討觸媒晶體結構、程序升溫還原(TPR)測定還原性、ASAP了解表面積的大小及FE-SEM觀察表面形貌，鑑定添加promoter的影響，改變了觸媒顆粒大小，增加了銅的分散性。並將觸媒填入填充式反應器，以反應條件：重量空間流速(WHSV=10 h-1)以氣相層析儀(GC-TCD)分析SRM反應後的氣體組成。 研究顯示，添加了Ce、Sm及Gd作為銅鋅觸媒的promoter的成果裡，以CuO/ZnO/Sm2O3/CeO2及CuO/ZnO/Gd2O3/CeO2這兩種觸媒活性最好，除了可以降低T95外，還可以增加YH2。為了使SRM反應產生的氫氣可以達到利用的效果，本研究嘗試自製的U型管填充式反應器，內可填充2.5 g的觸媒，結合了燃料電池使用，結果可以成功地產出20W的電力。
並列摘要
Recently, all of country accelerated the development of renewable resources. One of the promising renewable resources is hydrogen. Hydrogen is expected to play a major role in the future as a carbon free energy carrier. Steam reforming of methanol (SRM) is a reaction which may produce hydrogen for fuel cell application. Steam reforming of methanol was carried out over Cu-Zn catalysts prepared via the co-precipitation (CP) method. In this study, the addition of Sm and Gd in the catalyst composition affected the catalytic performance are developing. These metal oxides improved the activity of Cu–Zn catalysts, increase the selectivity of hydrogen and decrease concentration of CO. The advantage of Sm and Gd promotion have been characterized by techniques of the temperature programmed reduction (TPR), XRD, SEM, ASAP, and GC-TCD. XRD analysis of Gd and Sm doped catalysts showed that addition of dopants leads to increase of copper oxide dispersion. The reduction temperature of catalysts decreased from 230 to 190 oC due to the Sm and Gd promotion. The performance of catalysts was estimated from temperature required for 95% methanol conversion (T95) in SRM reaction. Consequently, T95 was significantly decreased to 240 oC.