燃料電池中氫氣來源主要是由液態碳氫化合物的重組轉換，其中以甲醇蒸氣重組反應即時產生氫氣，系統最簡單，適合移動式供氫，為目前最具潛力的產氫反應。甲醇蒸氣重組觸媒成分以CuO/ZnO/Al2O3為主，為了增加觸媒的活性與穩定性，有不少研究者引入CeO2、ZrO2，並對CeO2與ZrO2的優點做了很多的闡述，但是觸媒成分比例討論範圍偏狹，不具實用性。 本研究以商用觸媒G66B (CuO/ZnO/Al2O3 = 30/60/10)為參考成分，進行調變，以共沉澱法製備不同比例CuO/ZnO/CeO2/ZrO2/Al2O3觸媒，進行甲醇蒸氣重組反應，以期設計出最佳觸媒。 首先將商用比例觸媒中ZnO的一半30 wt%以不同比例CeO2/ZrO2取代，發現CeO2與ZrO2皆可以增加觸媒的分散性以及還原能力，可是CeO2的添加會使Al遷移至觸媒近表層，產生負面影響，而ZrO2的添加確實有促進效果。改變觸媒ZnO/ZrO2比例，發現以10~20 wt% ZrO2取代ZnO有最佳效果。改變觸媒基本成分CuO/ZnO/Al2O3中ZnO/Al2O3的比例，觸媒活性隨Al2O3增加而驟降，Al2O3雖然是負面影響，但仍扮演穩定觸媒、增加觸媒機械強度的角色，宜適量添加，如G66B之成分，10 wt%即可。CuO的負載量以CuO/ZnO/Al2O3(50/40/10)、CuO/ZnO/Al2O3(40/50/10)觸媒活性最佳，但Cu分散性差，且穩定測試中活性隨時間持續衰退。為了增加觸媒分散性與穩定性，分別以10~20 wt% ZrO2取代ZnO，製得活性、穩定性最佳觸媒為CuO/ZnO/ZrO2/Al2O3(40/30/20/10)。 On-board generation of hydrogen by methanol steam reforming is being used in the development of fuel-cell engines for various transportation applications. In the past the reaction was studied over CuO/ZnO/Al2O3-based catalyst. Previous studies have reported that CeO2 and ZrO2 both enhanced the reducibility of CuO, the Cu dispersion and the amount of Cu+, and those causes have been cited as a possible reason for the activity and stability promotion of catalyst. Although the advantages of CeO2 and ZrO2 have gone into details, their catalyst composition is limited. Our researchers varied commercial catalyst G66B composition (CuO/ZnO/Al2O3 = 30/60/10), and introduced CeO2 and ZrO2 simultaneously. In the methanol steam reforming, CeO2 inhibited the activity of catalyst because of the movement of Al atom. ZrO2 certainly enhanced the performance of catalysts, and 10~20 wt% ZrO2 was most effective for catalyst. Al2O3 which played the role of texture promoter inhibited the activity of catalyst seriously, need adding moderately. Varying the ratio of Cu/Zn, CuO/ZnO/Al2O3 (50/40/10) and CuO/ZnO/Al2O3 (40/50/10) showed better activity, but their stability was bad. In order to enhance the performance of catalyst, we introduced 10~20 wt% ZrO2, and produced the best catalyst CuO/ZnO/ZrO2/Al2O3 (40/30/20/10).
