Electrocatalytic Oxidation of Formaldehyde on Platinum under Galvanostatic and Potential Sweep Conditions Studied by Time-Resolved Surface-Enhanced Infrared Spectroscopy
Electrocatalytic Oxidation of Formaldehyde on Platinum under Galvanostatic and Potential Sweep Conditions Studied by Time-Resolved Surface-Enhanced Infrared Spectroscopy
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DOI：
10.1021/jp0743020
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发表时间：
2007-09
影响因子：
3.7
通讯作者：
G. Samjeské;and Atsushi Miki;M. Osawa
中科院分区：
文献类型：
--
作者：
G. Samjeské;and Atsushi Miki;M. Osawa
当甲醛在恒电流（恒流）条件下在铂电极上被氧化时，电极电势自发振荡。通过时间分辨表面增强红外吸收光谱 (SEIRAS) 检查振荡行为，以了解分子尺度的反应机制和动力学。 SEIRAS 揭示了 CO 和甲酸盐吸附在电极表面上，并且它们的带强度（覆盖范围）与电势振荡同步振荡。 SEIRAS 与循环伏安法或线性扫描伏安法结合表明，甲醛通过两个并行过程氧化为 CO2：通过吸附甲酸盐的直接路径和通过吸附 CO 的间接路径。这两个过程是动力学耦合的，并自动催化激活和失活甲醛氧化，从而产生电位振荡。电极表面的氧化也会导致大电流的振荡。
When formaldehyde is oxidized on a Pt electrode under galvanostatic (constant current) conditions, the electrode potential oscillates spontaneously. The oscillatory behavior has been examined by time-resolved surface-enhanced infrared absorption spectroscopy (SEIRAS) for understanding the mechanism and kinetics of the reaction at the molecular scale. SEIRAS reveals that CO and formate are adsorbed on the electrode surface and that their band intensities (coverages) oscillate synchronously with the oscillation of potential. SEIRAS coupled to cyclic voltammetry or linear sweep voltammetry suggests that formaldehyde is oxidized to CO2 via two parallel processes: the direct path via adsorbed formate and the indirect path via adsorbed CO. The two processes are kinetically coupled and autocatalytically activate and deactivate formaldehyde oxidation to yield the potential oscillations. The oxidation of the electrode surface also contributes to the oscillations for large applied currents.