Current oscillations during the oxidation of formic acid on Pt(100) as studied by in situ time-resolved infrared reflection absorption spectroscopy
Current oscillations during the oxidation of formic acid on Pt(100) as studied by in situ time-resolved infrared reflection absorption spectroscopy
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DOI：
10.1016/s0009-2614(97)00601-5
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发表时间：
1997-07-18
影响因子：
2.8
通讯作者：
Ito, M
中科院分区：
文献类型：
--
作者：
Honda, Y;Song, MB;Ito, M
采用时间分辨红外反射吸收光谱（IRAS）在稀高氯酸水溶液中研究了 Pt(100) 单晶电极上甲酸电化学氧化的电流振荡。通过改进光谱电化学池的功能设计，使原位 IRAS 测量成为可能。当振荡发生时，在光谱中观察到两种不同类型的顶部 CO 吸收。在振荡尖峰底部（所谓的非活动状态）观察到 2060 cm(-1) 处的较高频带，在尖峰顶部（所谓的活动状态）2050 cm(-1) 处观察到较低频带。另一方面，二氧化碳的产生量（来自有机中间体）保持恒定，与振荡的峰值无关。这些结果并不支持传统观点，即吸附 CO 物质的氧化去除和积累是振荡的根源，而是支持一种修正的观点，即振荡是由电极上吸附 CO 存在时 OH 物质的吸附和解吸引起的。 (C) 1997 Elsevier Science B.V.
Current oscillations in the electrochemical oxidation of formic acid on a Pt(100) single crystal electrode were studied by time-resolved infrared reflection absorption spectroscopy (IRAS) in a dilute perchloric acid aqueous solution. In situ IRAS measurements were made possible by improving functional designs in an spectroelectrochemical cell. Two different kinds of on-top CO absorptions were observed in the spectra while the oscillations were taking place. A higher frequency band at 2060 cm(-1) was observed at the bottom of the oscillation spikes (so-called inactive states) and the lower one at 2050 cm(-1) at the top of the spikes (active states). On the other hand, the amount of CO2 production (which was derived from organic intermediates), remained constant irrespective of the spikes in the oscillations. These results do not support the traditional view that the oxidative removal and accumulation of adsorbed CO species are the origin of the oscillations, rather they support a modified view that they are caused by the adsorption and desorption of OH species in the presence of adsorbed CO on the electrode. (C) 1997 Elsevier Science B.V.