In Situ Spectroscopy Study of Oxygen Reduction Reaction Intermediates at the Pt/Acid Interface: Surface-Enhanced Infrared Absorbance Spectroscopy
In Situ Spectroscopy Study of Oxygen Reduction Reaction Intermediates at the Pt/Acid Interface: Surface-Enhanced Infrared Absorbance Spectroscopy
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DOI：
10.1021/acs.jpcc.9b11950
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发表时间：
2020-04-02
影响因子：
3.7
通讯作者：
Noguchi, Hidenori
中科院分区：
文献类型：
--
作者：
Kukunuri, Suresh;Noguchi, Hidenori
对开发高效的电化学能量系统（例如燃料电池和金属-空气电池）的日益增长的需求已经刺激了研究兴趣，研究与这些系统直接相关的在催化剂表面处的氧还原反应（ORR）的机理途径。尽管过去几年中很少有人致力于说明在各种pH条件下ORR的机理途径，但在酸性条件下产生的中间体的化学性质仍然是一个挑战。在本研究中，可能的中间物种形成在Pt/HClO 4界面的检测是endeavourable使用原位表面增强红外吸收光谱（SEIRAS）。这是实现使用一个简单的电极配置与多晶铂沉积在粗糙表面的Au-涂层的ZnSe棱镜，以避免红外吸收的棱镜。电位依赖性的SEIRAS测量表明在Pt表面形成超氧阴离子物种。O-同位素（O-18（2））和D2 O条件下的光谱分析证实了超氧化物物种的检测。对ORR中间体及其表面覆盖率的系统研究为高效催化剂设计铺平了道路。
Increasing demands for the development of efficient electrochemical energy systems such as fuel cells and metal-air batteries have stimulated research interests in investigating the mechanistic pathway of the oxygen reduction reaction (ORR) at the catalyst surface, having direct relevance to these systems. Although past years have witnessed few efforts toward illustrating the mechanistic pathway of the ORR under various pH conditions, the chemical nature of intermediates generated under the acidic conditions still remains a challenge. In the present study, the detection of possible intermediate species formed at the Pt/HClO4 interface is endeavored using in situ surface-enhanced infrared absorbance spectroscopy (SEIRAS). This is achieved using a simple electrode configuration with polycrystalline Pt deposited on the roughened surface of an Au-coated ZnSe prism to avoid the IR absorbance of the prism. Potential-dependent SEIRAS measurements demonstrate the formation of superoxide anion species at the Pt surface. Spectral analysis under O-isotope (O-18(2)) and D2O conditions corroborate the detection of superoxide species. A systematic study of the ORR intermediates and their surface coverage paves a way for efficient catalyst design.