Electrochemically reduced Pt oxide thin film as a highly active electrocatalyst for direct ethanol alkaline fuel cell
Electrochemically reduced Pt oxide thin film as a highly active electrocatalyst for direct ethanol alkaline fuel cell
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DOI：
10.1016/j.ijhydene.2014.09.038
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发表时间：
2014-10
影响因子：
7.2
通讯作者：
Hiroki Takahashi;Masanao Sagihara;M. Taguchi
中科院分区：
文献类型：
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作者：
Hiroki Takahashi;Masanao Sagihara;M. Taguchi
采用反应溅射法制备了Pt氧化物薄膜和Pt薄膜，并研究了其在KOH溶液中对乙醇氧化反应的电催化活性，用于碱性直接乙醇燃料电池的开发。在通过阴极电荷的电化学还原之后，Pt氧化物薄膜显示出比Pt薄膜大29倍的乙醇氧化电流。这种上级活性是由电化学活性表面积的增加和残余氧的存在引起的，这由循环伏安法和XPS测量证实。由于残余氧的贡献，乙醇氧化反应的速率控制步骤可能会发生变化，因为在乙醇氧化反应过程中，Pt氧化物薄膜的Tafel斜率被电化学还原改变。尽管Pt氧化物薄膜中的总Pt量小于Pt薄膜中的总Pt量，但Pt氧化物薄膜显示出优异的乙醇氧化活性。因此，经电化学还原处理后的Pt氧化物有望成为直接乙醇燃料电池的阳极催化剂。
The Pt oxide thin film and Pt thin film were prepared by reactive sputtering and the electrocatalytic activity of the ethanol oxidation reaction was investigated in a KOH solution for developing the alkaline direct ethanol fuel cells. After electrochemical reduction by passing a cathodic electric charge, the Pt oxide thin film showed 29 times larger ethanol oxidation current than the Pt thin film. This superior activity was caused by an increase in the electrochemical active surface area and the existence of residual oxygen, which was confirmed by cyclic voltammetry and XPS measurement. Due to the contribution of the residual oxygen, the rate-determining step of the ethanol oxidation reaction might change, because the Tafel slope of the Pt oxide thin film during the ethanol oxidation reaction was changed by electrochemical reduction. Despite the total Pt amount in the Pt oxide thin film being smaller than that in the Pt thin film, the Pt oxide thin film showed excellent ethanol oxidation activity. Therefore, the Pt oxide treated by electrochemical reduction may be a promising anode catalyst for the direct ethanol fuel cells.