以鉑原子團簇修飾錫核鈀殼結構增強鉑於氧氣還原反應之質量活性之探究

本研究利用濕式化學還原法，以硼氫化鈉(NaBH4)作為還原劑，依序將錫、鈀、鉑金屬離子還原至多層奈米碳管，形成錫核鈀殼結構外層修飾鉑金屬團簇的三元(素)奈米金屬粒子，作為燃料電池陰極觸媒材料，將鉑金屬負載量降至5~13 wt%，與商業鉑金屬觸媒(J.M.-Pt/C)鉑金屬附載量(20 wt%)相比，大幅降低鉑金屬負載量，經鹼性環境下做電化學實驗，其氧氣還原反應位於0.85 V vs RHE的電位下質量活性(M.A.Pd+Pt)為J.M.-Pt/C的兩倍。　　本研究分為三個部分，藉由不同核殼式結構觸媒(Sn@Pd, Sn)與三元觸媒(Pt/Sn@Pd)進行比較，確認三元觸媒的確優於二元觸媒。並改變三元觸媒鉑金屬負載量，以探究不同鉑金屬團簇的分散性與大小對於氧氣還原活性的影響氧氣還原活性的影響。　　本實驗藉由第二種或第三種元素的添加、退火的控制確定了不同鉑金屬結構的變化與觸媒氧氣還原反應之活性之關聯性，並有效的增加其催化電流與減少鉑金屬的使用率，將增加陰離子交換膜燃料電池(AEMFC)發展潛力。

關鍵字

鉑原子；氧化；還原；燃料電池；觸媒；循環伏安法；線性掃描伏安法；電化學；光鑷子

並列摘要

The Pt/Sn@Pd NC is synthesized with ternary metallic, copper, palladium and Platinum by using wet chemical reduction method, which configuration of NC is a Sn@Pd core and atomic Pt clustersin the top. Pt are well known for their unique electrocatalytic properties but it’s expensive. In this experiment design, to reduce the cost and enhance oxygen reduction reaction (ORR), the reduction of atomic Pt clusters loading in Pt/Sn@Pd NC (5~13 wt %) compares with commercial Pt catalysts (20 wt %). At 0.85 volt (vs RHE), the mass activity (MA) of Pt/ Sn@Pd NC which is 2-times higher than Pt catalysts. In this dissertation, compared the properties of dispersivity and size of Pt clusters and stability in ORR with (ⅰ) ternary metallic NC (Pt/Sn@Pd) and binary metallic catalyst (Sn@Pd, Sn) (ⅱ) difference Pt clusters loading in Pt/Sn@Pd (ⅲ) annealing of ternary metallic NC. In addition, Binding energy is verified that the electrons are obviously transferred from Sn to Pt and higher activity for ORR.Finally, the annealing of ternary metallic catalysts (Pt/Sn@Pd) are certainly clusters and alloy of Pt structure which is related to activity in ORR. Additionally, Pt/Sn@Pd potentially enhances the current of ORR and reduction amount of Pt. thereby, ternary metallic Pt/Sn@Pd catalyst was better in binary metallic catalyst and commercial Pt so Pt/Sn@Pd was selected to be catalyst.

並列關鍵字

Heterogeneous ； Oxygen Reduction Reaction ； Pt Clusters ； Mass Activity ； catalyst ； Cyclic Voltammetry

參考文獻

10. A. S. Xiaoming Ge, † Delvin Wuu,† Tao An,† Bing Li,† F. W. Thomas Goh,† and T. S. Andy Hor, †,‡ Yun Zong,*,† and Zhaolin Liu*,†, ACS Catalysis, 2015, DOI: 10.1021/acscatal.5b00524, 4643-4667.

1. J. Wisniak, Indian Journal of History of Science, 2015, 50.