第四章 結論
本實驗中成功的利用水熱法合成出 CexZr1-xO2之固溶體，由表 4-1 可知，當 x=0.1、0.2、0.25、0.9 時均可以得到單一相且分佈均勻的奈 米粒子；當 x=0.8 時可以成功的合成出奈米柱構形，由表 4-3 可知，
調控反應時間可以控制奈米柱之長短大小，由 HR-TEM 中可以觀察 到其生長發向應沿[110]方向；而由表 4-4 可知，當 x=0.9 時則合成出 奈米方塊，當反應時間所短時可改變構形變成奈米柱形狀，拉長反應 時間或改變含鋯之前驅物，則變成不規則奈米粒子，由高解析穿透式 電子顯微鏡中可以看到兩個平行的[100]晶格方向，故推測方塊應由 {100}的面所組成。而利用微量的氧化鋯粉末則可成功的合成出氧化 鈰的奈米管，由高解析顯微鏡中可以得知應為單晶形式的奈米管構 形。
上述之產物均經感應耦核電漿質譜分析、穿透式/掃瞄式電子顯 微鏡之能量散射光譜分析與映射圖譜分析來確認其產物與初始反應 比例相當接近。
由表 4-2 可知，在乙醇轉氫的實驗中，以 CexZr1-xO2之固溶體為 催化劑，摻雜氧化物的重量比 5%之銠金屬所做的結果發現效率也可 達到 110%以上，而當摻雜 5%之釕金屬時，發現氧化鈰奈米方塊、氧 化鈰奈米管、Ce0.9Zr0.1O2(奈米方塊)及 Ce0.8Zr0.2O2(奈米柱)，在適當條 件下有 110%以上之氫氣選擇率。由於釕金屬比銠金屬便宜很多，再 加上摻雜鋯元素有較高之熱穩定性，由此可以發現此類固溶體之結果 對乙醇轉氫實驗而言，為相當具有潛力之材料。
CexZr1-xO2 最佳氫氣選擇率(%) ZrO2 (particle) 107
Ce0.1Zr0.9O2 (particle) 99.8 Ce0.2Zr0.8O2 (particle) 110.7 Ce0.25Zr0.75O2 (particle) 90.1
Ce0.5Zr0.5O2 (particle) 90.1 Ce0.8Zr0.2O2 (rod) 101.2 Ce0.9Zr0.1O2 (cube) 111.8 CeO2 (cube) 110.1 CeO2 (rod) 105 CeO2 (tube) 113.5
表 4-2 5%Ru 與不同比例之 CexZr1-xO2之最佳氫氣選擇 率
Ce
xZr
1-xO
2構形 ZrO
2particle Ce
0.1Zr
0.9O
2particle Ce
0.2Zr
0.8O
2particle Ce
0.25Zr
0.75O
2particle
Ce
0.8Zr
0.2O
2rod Ce
0.9Zr
0.1O
2cube
表 4-1 利用硝酸鈰及二硝酸基氧化鋯水熱法反應 48 小時，成 功合成出單一純相之 CexZr1-xO2及其構形。
72
表 4-3 Ce0.8Zr0.2O2依比例之硝酸鈰加入二硝酸基氧化鋯經過不同水 熱反應時間及不同鹼性濃度之所得到之構形。
表 4-4 Ce0.9Zr0.1O2利用不同水熱反應時間及前驅物所得到之構形。
Formula Base (M) Temp (
oC) Time (hr) XRD Result Morphology Ce
0.8Zr
0.2O
2NaOH (15M) 150 48 CeO
2rod Ce
0.8Zr
0.2O
2NaOH (15M) 150 24 CeO
2rod Ce
0.8Zr
0.2O
2NaOH (15M) 150 60 CeO
2particle Ce
0.8Zr
0.2O
2NaOH (12M) 150 48 rod+particle Ce
0.8Zr
0.2O
2NaOH (18M) 150 48 rod+particle
Formula Reagent Time (hr) XRD Result Morphology
Ce
0.9Zr
0.1O
2Ce(NO
3)
3·6H
2O+ZrO(NO
3)
224 CeO
2rod
Ce
0.9Zr
0.1O
2Ce(NO
3)
3·6H
2O+ZrO(NO
3)
236 CeO
2cube+rod
Ce
0.9Zr
0.1O
2Ce(NO
3)
3·6H
2O+ZrO(NO
3)
248 CeO
2cube
Ce
0.9Zr
0.1O
2Ce(NO
3)
3·6H
2O+ZrO(NO
3)
260 CeO
2irregular
Ce
0.9Zr
0.1O
2Ce(NO
3)
3·6H
2O+Zr(OH)
424 CeO
2particle
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