A Survey of Size-Selected Subnanometer Catalysts for Fuel Cells

燃料电池尺寸选择亚纳米催化剂的调查

• 批准号: 183236109
• 负责人: Dr. Sebastian Proch
• 金额: --
• 依托单位: Fachbereich Physik
• 依托单位国家: 德国
• 项目类别: Research Fellowships
• 财政年份: 2010
• 资助国家: 德国
• 起止时间: 2009-12-31 至 2011-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/183236109?language=en
• 关键词: Survey; Size; Selected; Subnanometer; Catalysts

One of the major issues hampering further commercialization of fuel-cell technology is the precious metal content in the cells. Hence creating higher active surfaces at lower precious metal content, i.e. smaller particles, is a research topic of utmost importance. Recent results obtained on size-selected platinum subnanometer catalysts (Pt12, Pt28 and Pt60) synthesized by use of a dendrimer template indicate a 12 times higher mass activity compared to state of the art Pt/C catalysts. The chemical synthesis of size-selected platinum clusters does not allow for a preparation of all desired cluster sizes. Another drawback is that the dendrimer template cannot be removed, which may lead to decreased catalytic activity. Here a survey of size-selected subnanometer platinum catalysts from Pt1 to Pt20 is proposed. The size-selected “naked” particles will be deposited from the gas phase onto glassy carbon electrodes by the means of cluster science and the oxygen reduction activity will be determined by in-situ measurements completely under UHV conditions and ex-situ by rotating ring disk electrode measurements. A complete survey of the size-dependence of the oxygen reduction activity of size-selected (monodisperse) subnanometer platinum clusters will be carried out in order to find the most active oxygen reduction catalyst for fuel cell applications. In addition to simple activity studies the most promising clusters will be subject to long-term stability studies by cycling experiments. The investigation of the clusters and the electrode surface by a combination of X-ray photoemission spectroscopy (XPS), low energy ion scattering spectroscopy (ISS) and temperature programmed desorption (TPD) before and after electrocatalysis will reveal useful information on catalyst degradation mechanisms on the micrometer and the nanometer scale.

阻碍燃料电池技术进一步商业化的主要问题之一是电池中的贵金属含量。因此，在较低的贵金属含量下产生更高的活性表面，即更小的颗粒，是一个非常重要的研究课题。通过使用树枝状聚合物模板合成的尺寸选择的铂亚纳米催化剂（Pt 12、Pt 28和Pt 60）上获得的最新结果表明，与现有技术的Pt/C催化剂相比，质量活性高12倍。尺寸选择的铂簇的化学合成不允许制备所有期望的簇尺寸。另一个缺点是树枝状聚合物模板不能被去除，这可能导致催化活性降低。本文综述了从Pt 1到Pt 20的尺寸选择性亚纳米铂催化剂。通过簇科学的手段将尺寸选定的“裸”颗粒从气相沉积到玻碳电极上，并且将通过完全在UHV条件下的原位测量和通过旋转环盘电极测量的非原位测量来确定氧还原活性。将进行一个完整的调查，以找到最活跃的氧还原催化剂的燃料电池应用的尺寸选择（单分散）亚纳米铂簇的氧还原活性的尺寸依赖性。除了简单的活性研究外，最有希望的簇将通过循环实验进行长期稳定性研究。结合X射线光电子能谱（XPS）、低能离子散射谱（ISS）和程序升温脱附（TPD）等技术对电催化前后的团簇和电极表面进行研究，将在微米和纳米尺度上揭示催化剂降解机理的有用信息。