Abstract：
The interaction between organic molecules and oxidized catalyst surfaces has frequently been used to study the fuel crossover from the anode to the cathode in direct liquid fuel cells. In such experiments, the oxidized surface is put in contact with the fuel under open circuit conditions, and the evolution of the potential is registered. The open circuit potential (OCP) vs. time features can then inform on the reactivity of the fuel with the oxidized surface and provide valuable information not only to applications in fuel cells but also to the electrochemical reform of those molecules to produce clean hydrogen. In this paper, we present an experimental investigation of the open circuit interaction between ethanol or 2-propanol with oxidized platinum surfaces. Besides the OCP time traces, we have also employed cyclic voltammetry and fast oxide reduction sweep in the presence of the alcohols. Comparable reaction currents are obtained in the cyclic voltammogram, but the electro-oxidation of 2-propanol sets in at considerably lower overpotentials than that of ethanol. At the high potential region, both the magnitude and the potential of the current peak are nearly identical in both cases. In contrast, under open circuit conditions, the interaction of ethanol with the oxidized platinum surface is more pronounced than that found for 2-propanol, and these results are corroborated by the facile reduction of the platinum oxides along the fast backward sweep for the case of the latter.
摘要：
有机分子与氧化催化剂表面之间的相互作用已用于研究直接液体燃料电池中从阳极到阴极的燃料交叉。在这样的实验中,氧化表面在开路条件下与燃料接触，潜力被登记。然后,开路电势(OCP)可以告知燃料与氧化表面的反应性并提供有价值的信息。在此，我们对乙醇或2-丙醇与氧化铂表面之间的OC相互作用进行了实验研究。除了OCP,我们还采用了循环伏安法和在醇存在下的快速氧化还原扫描。在伏安图中获得了相当的反应电流，但是2-丙醇的电氧化比乙醇的过电位低得多。在高电位区,在两种情况下，电流峰值的大小和电势几乎相同。在开路条件下，乙醇与氧化铂表面的相互作用比2-丙醇更明显，这些结果被铂氧化物沿后者的快速向后扫描的容易还原所证实。
