結果之討論

醇氧化反應之電流，所以不可只考慮尺寸與電荷轉移之間的效應。但 Pt 表

25 圈一氧化碳氧化電位較高，Pt 表面可能以 Pt(100)為主，第 40、45、50 圈，Pt 表面可能以 Pt(111)為主，而第 30、35 圈，Pt 表面則以 Pt(110)為主。

以上之結果與討論有一個共通點，在 ALD Pt 圈數多的時候(第 40、45、

50 圈)，Pt 表面主要之晶面為 Pt(111)，由 XRD、氫吸脫附反應、TEM 影像 接有觀察到隨著 ALD Pt 圈數增加，Pt(111)越容易被觀察到。根據文獻【46】，

XPS Ti 2p 訊號形狀可知(圖 4-50，最下層)，Pt 薄膜之厚度為 3.78nm，符合

圖 4-44 SEM、TEM 尺寸 隨著 ALD Pt 圈數改變之關係圖

圖 4-45 ICP-MS 白金負載量隨著 ALD Pt 圈數改變之關係圖

圖 4-46 電化學活性面積隨著 ALD Pt 圈數改變之關係圖

圖 4-47 If/Ib 隨著 ALD Pt 圈數改變之關係圖

圖 4-48 甲醇氧化反應之電流與電位隨著 ALD Pt 圈數改變之關係圖

圖 4-49 一氧化碳氧化電位隨著 ALD Pt 圈數改變之關係圖

圖 4-50 在 Pt/TiO2 系統中隨著 Pt 薄膜厚度改變之 XPS Ti 2p 與 Pt 4f 訊號

【46】

第五章 結論與未來展望

7. 隨著白金奈米粒子尺寸的縮小，If/Ib比值上升，抗一氧化碳毒化的能力變 好，歸功於白金奈米粒子與二氧化鈦基材之間的電荷轉移作用與雙官能基 效應。

8. 根據 XPS 的分析結果，可以發現到白金奈米粒子和二氧化鈦基材之間的 電荷轉移，這可能是弱化一氧化碳鍵結、提升一氧化碳容忍度的關鍵。

9. 利用氫電漿前處理可以在較少的原子層沉積圈數沉積出密度大的白金奈 米粒子。

未來展望

將二氧化鈦基材的表面粗糙度增加或是使用高表面積的二氧化鈦基材 (例如，二氧化鈦奈米顆粒)，或是利用氫電漿前處理，提升白金奈米粒子的 密度，增加白金觸媒的表面積，而提升電化學活性面積，並且利用真空退 火使二氧化鈦基材的導電度增加，讓甲醇氧化反應產生的電子能夠順利的 傳導至外部電路。另外，根據文獻，可利用 UV 光輔助甲醇在二氧化鈦上 之光催化，增加燃料電池陽極輸出之電流值。在觸媒方面，可使用二元合 金(例如，Ru-Pt)，並觀察利用原子層沉積系統沉積出的二元合金在二氧化 鈦基材上的甲醇氧化反應之效果。

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