Ragassi Gianluca, Dourado André H B, Varela Hamilton
São Carlos Institute of Chemistry, University of São Paulo, PO Box 780, 13560-970, São Carlos, SP, Brazil.
Phys Chem Chem Phys. 2023 Dec 6;25(47):32345-32355. doi: 10.1039/d3cp03995a.
The oscillatory electro-oxidation of 2-propanol on platinum and platinum-based catalysts has attracted growing attention in recent years due to its importance in the interconversion between chemical and electrical energies. This reaction might proceed with a very high selectivity to acetone, nearly without the formation of carbon dioxide, and the reversibility of the 2-propanol/acetone pair is very appropriate for hydrogen transfer. An important aspect of this system is the ubiquitous emergence of potential oscillations under current control, and it has been pointed out as a problem to be avoided and a primary cause of limitations to the use of 2-propanol in practical devices. Herein, we present an experimental study of the electrochemical instabilities in the electro-oxidation of 2-propanol on platinum. The system was studied using polycrystalline platinum, in acidic media and at different temperatures. Besides the extensive characterization of the potential oscillations, we have also discussed possible venues for engineering the dynamics to benefit from the potential oscillations. In this sense, we have also characterized the instabilities in the system containing a mixture of 2-propanol and methanol. The efficiency of a hypothetical fuel cell operated under different conditions is also presented.
近年来，2-丙醇在铂及铂基催化剂上的振荡电氧化因其在化学能与电能相互转换中的重要性而受到越来越多的关注。该反应可能以对丙酮非常高的选择性进行，几乎不生成二氧化碳，并且2-丙醇/丙酮对的可逆性非常适合氢转移。该系统的一个重要方面是在电流控制下普遍出现电位振荡，并且这已被指出是一个需要避免的问题以及限制2-丙醇在实际装置中使用的主要原因。在此，我们展示了关于2-丙醇在铂上电氧化过程中电化学不稳定性的实验研究。该系统在酸性介质中、不同温度下使用多晶铂进行研究。除了对电位振荡进行广泛表征外，我们还讨论了操纵动力学以从电位振荡中受益的可能途径。从这个意义上讲，我们还表征了含有2-丙醇和甲醇混合物的系统中的不稳定性。还展示了在不同条件下运行的假设燃料电池的效率。
