SGER: Platinum Nanofibers as Fuel Cell Electrodes

SGER：铂纳米纤维作为燃料电池电极

• 批准号: 0801402
• 负责人: James Li
• 金额: $ 17万
• 依托单位: University of Rochester
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-03-01 至 2010-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0801402&HistoricalAwards=false
• 关键词: SGER; Platinum; Nanofibers; Fuel; Cell

TECHNICAL: Since platinum (Pt) is an effective catalyst but an expensive metal, a structure with a large surface-to-volume ratio is needed to minimize its use. All the available techniques require a support and a good adherence between the support such as carbon and nanoparticles of Pt. The adhesion is generally not good and this is a major source of the durability problem one faces in applications such as fuel cells. A free-standing pure Pt network would also be a welcome ingredient in many other chemical applications and processes, and its development is the focus of this high-risk, high payoff, and transofrmative SGER project. By using a Pt chain compound similar to Magnus green salt, PI can produce a nanowire network of Pt suitable for fuel cell electrodes. However, the size of wire is large. PI would reduce the size to 10 nm. This pure Pt free-standing electrode with or without a support should be more efficient than the ones so far available in which Pt nanoparticles are dispersed in a porous carbon support. In addition, PI can produce nanowires of Pt and Pt/Ni alloys by electro-spinning. The diameter is about 20 nm. PI would aim to get smaller diameters so as to further reduce the use of Pt. These wires can stand alone or mingle with carbon fibers to make electrodes. The high payoff, transformative characteristics of this work would be that without migrating nanoparticles, the wires would be more stable so the resulting fuel cells would be more durable. This design will also be more stable since there are no nanoparticles which could migrate and agglomerate. While the payoff is huge, there are three areas of risk that must be managed and overcome. One is the 3-phase contact points. PI would have to ensure that there are enough 3-phase (gas, electrolyte and electrode) contact points for efficient cell operation. The second is the mechanism of agglomeration. It must be the migration and coalescence of small particles in order to have the benefits of nanowires. The third is the resistivity of nanowires. For that PI plans to plate Pt onto the micro-wires of support. NON-TECHNICAL: Metals are usually in a bulk solid form including fine powders, wires and thin films. Hence it is a challenge to make nanowire network of Pt by chemical means. It requires both the knowledge in chemistry and in materials science. Chemistry is needed to understand the reactions involved and materials science to see how the microstructure was evolved. PI plans to combine these two elements in this SGER research towards the development of robust and efficient electrodes for fuel cells for energy applications. The PI has a doctorate in chemistry but also has many years experience in materials research. He is assisted with a graduate student in Chemical Engineering who has experience in chemical synthesis and another one in materials science who has experience in nanowires. Fuel cell is also an attractive area for graduate, undergraduate, and high school students. PI would involve them and make them aware of the current energy problems.

技术：由于铂 (Pt) 是一种有效的催化剂，但也是一种昂贵的金属，因此需要具有大表面积与体积比的结构以最大限度地减少其使用。所有可用的技术都需要支撑物以及碳和 Pt 纳米颗粒等支撑物之间的良好粘附力。粘附力通常不好，这是燃料电池等应用中面临的耐久性问题的主要原因。独立的纯铂网络也将成为许多其他化学应用和工艺中受欢迎的成分，其开发是这个高风险、高回报和转型 SGER 项目的重点。通过使用类似于马格努斯绿盐的Pt链化合物，PI可以产生适用于燃料电池电极的Pt纳米线网络。然而，电线的尺寸很大。 PI 会将尺寸减小至 10 nm。这种带有或不带有支撑物的纯 Pt 自立式电极应该比迄今为止可用的 Pt 纳米颗粒分散在多孔碳支撑物中的电极更有效。此外，PI还可以通过静电纺丝生产Pt和Pt/Ni合金纳米线。直径约为20纳米。 PI的目标是获得更小的直径，以进一步减少Pt的使用。这些电线可以单独使用，也可以与碳纤维混合制成电极。这项工作的高回报、变革性特征是，如果不迁移纳米颗粒，电线将更加稳定，因此最终的燃料电池将更加耐用。这种设计也将更加稳定，因为没有可以迁移和团聚的纳米颗粒。尽管回报巨大，但仍必须管理和克服三个方面的风险。一是三相接触点。 PI 必须确保有足够的三相（气体、电解质和电极）接触点以实现电池的高效运行。二是集聚机制。必须是小颗粒的迁移和聚结才能具有纳米线的优点。第三是纳米线的电阻率。为此，PI 计划将 Pt 镀到微支撑线上。非技术性：金属通常呈块状固体形式，包括细粉末、线材和薄膜。因此，通过化学方法制备Pt纳米线网络是一个挑战。它需要化学和材料科学方面的知识。需要化学来理解所涉及的反应，需要材料科学来了解微观结构是如何演变的。 PI 计划在 SGER 研究中将这两个要素结合起来，为能源应用燃料电池开发坚固、高效的电极。 PI拥有化学博士学位，同时也拥有多年材料研究经验。他得到了一名具有化学合成经验的化学工程研究生和另一名具有纳米线经验的材料科学研究生的协助。燃料电池对于研究生、本科生和高中生来说也是一个有吸引力的领域。 PI 会让他们参与进来，让他们意识到当前的能源问题。