Electrochemical oxidation of four different alcohol molecules (methanol, ethanol, n-butanol and 2-butanol) at electrodeposited Pt film and carbon-supported Pt catalyst film electrodes, as well as the effect of mass transport on the oxidation reaction, has been studied systematically using the rotating disk electrode (RDE) technique. It was shown that oxidation current decreased with an increase in the rotation rate (ω) for all alcohols studied over electrodeposited Pt film electrodes. In contrast, the oxidation current was found to increase with an increase in the ω for Pt/C in ethanol and n-butanol-containing solutions. The decrease was found to be nearly reversible for ethanol and n-butanol at the electrodeposited Pt film electrode ruling out the possibility of intermediate COads poisoning being the sole cause of the decrease and was attributed to the formation of soluble intermediate species which diffuse away from the electrode at higher ω. In contrast, an increase in the current with an increase in ω for the carbon supported catalyst may suggest that the increase in residence time of the soluble species within the catalyst layer, results in further oxidation of these species. Furthermore, the reversibility of the peak current on decreasing the ω could indicate that the surface state has not significantly changed due to the sluggish reaction kinetics of ethanol and n-butanol.

中文翻译：

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传质对醇在电沉积膜和碳载Pt电极上的电化学氧化的影响。

已经系统地研究了电沉积的Pt膜和碳载Pt催化剂膜电极上四种不同醇分子（甲醇，乙醇，正丁醇和2-丁醇）的电化学氧化，以及传质对氧化反应的影响。使用旋转圆盘电极（RDE）技术。结果表明，对于在电沉积的Pt膜电极上研究的所有醇，氧化电流随转速（ω）的增加而降低。相反，发现在乙醇和含正丁醇的溶液中，Pt / C的氧化电流随ω的增加而增加。发现在电沉积的Pt膜电极上乙醇和正丁醇的下降几乎是可逆的，排除了中间COads中毒是下降的唯一原因，并且归因于形成了从中间扩散而来的可溶性中间物质。电极在较高的ω。相反，对于碳负载催化剂，电流随ω的增加而增加可能表明可溶性物质在催化剂层内停留时间的增加导致这些物质的进一步氧化。此外，减小ω时峰值电流的可逆性可能表明，由于乙醇和正丁醇的反应动力学缓慢，表面状态没有明显改变。