Periodic Pulsed-Potential Electrolysis of Methanol

这是对周期性脉冲电位 在未改性的铂电极上电解，或结合 通过欠电位沉积锡进行表面改性，或 钌，可以显着增加循环平均功率 通过降低有毒副产物的浓度来生产 吸附在电极上。 对于周期的一小部分， 阳极电势被脉冲到高值，在该高值处， 被氧化去除;在循环的剩余部分期间，阳极 电势处于较低的产生功率的极化。 初步 结果表明，平均电流可以增加更好的 两个数量级以上，可通过使用稳定- 状态（DC）控制在相同的电源电位。 的影响 酸性甲醇溶液脉冲电位电解 和碳载铂，有或没有欠电位- 沉积的锡或钌。 常规电流- 电压-时间电化学测量，记录和表面 红外和X射线光电子能谱。 生产 甲醛和甲酸的溶解速率以及 铂在脉冲电位电解的影响下， 测定 甲醇-空气燃料电池对许多人来说是有吸引力的电源。 应用，包括电动汽车、远程安装， 运输系统和紧急备用系统 甲醇 更便宜，更紧凑，更容易运输，使用更安全 氢是主要的替代燃料电池燃料。 不幸的是，使用铂的甲醇-空气燃料电池 电催化剂是自中毒的，严重限制了它们的 效率 这项工作解决了这个缺点。

This is a test of the hypothesis that periodic, pulsed-potential electrolysis on an unmodified platinum electrode, or in conjunction with surface modification by underpotential-deposited tin or ruthenium, can significantly increase the cycle-averaged power production by lowering the concentration of the poisonous byproduct adsorbed on the electrode. For a small fraction of the cycle, the anode potential is pulsed to a high value at which the surface poison is oxidatively removed; during the remainder of the cycle, the anode potential is at a lower, power-producing polarization. Preliminary results suggest that the average current may be increased by better than two orders of magnitude above that obtainable by using steady- state (DC) control at the same power potential. The effects of pulsed-potential electrolysis in acidic methanol solutions on smooth and carbon-supported platinum, with and without underpotential- deposited tin or ruthenium, are investigated. Conventional current- voltage-time electrochemical measurements, are recorded and surface infrared and X-ray photoelectron spectra are taken. The production rates of formaldehyde and formic acid and the dissolution rate of platinum under the influence of pulsed-potential electrolysis are determined. Methanol-air fuel cells are attractive power sources for many applications, including electric vehicles, remote installations, transportation systems, and emergency backups. Methanol is cheaper, more compact, easier to transport, and much safer to use than hydrogen, which is the principal alternative fuel-cell fuel. Unfortunately, methanol-air fuel cells using a platinum electrocatalyst are self poisoning, severly limiting their efficiency. This work addresses this shortcoming.