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Development and Application of a Flexible Synthesis for Unprotected Colloidal Pt Nanoparticles as a Platform for Systematic Degradation Studies in Electrocatalysis

无保护胶体铂纳米粒子的灵活合成的开发和应用作为电催化系统降解研究的平台

基本信息

批准号：
354106573
负责人：
Professor Dr.-Ing. Bastian Etzold, since 12/2018
金额：
--
依托单位：
Institut für Angewandte und Physikalische Chemie
依托单位国家：
德国
项目类别：
Research Grants
财政年份：
2017
资助国家：
德国
起止时间：
2016-12-31 至 2020-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/354106573?language=en
关键词：
Development Application Flexible Synthesis Unprotected

项目摘要

The direct use of H2 as an energy carrier is one possible scenario for the switch from nuclear power and fossil fuels to regenerative energy. The fuel cell technology is thereby of significant relevance and the optimization of activity and stability are essential challenges in order to foster their applicability. While the catalytic activity has been investigated quite intensively in the past and active material have been developed, knowledge about relations between the catalyst properties and the stability are still scarce. The primary goal for the proposed project is to establish a preparation platform that enables for systemic investigations of the influence of the most relevant catalyst properties (particle size, loading, and support) on the performance and hence also the catalyst stability. For state-of-the-art fuel cell catalysts (carbon supported Pt nanoparticles) this task can basically be addressed using so-called unprotected Pt nanoparticles (NPs). Such NPs are synthesized as colloids in alkaline ethylene glycol. The application of further preparation steps enables for depositing these particles onto every type of support material. As a result support and particle loading can be controlled independently. However, the application of unprotected NPs is still hindered by the limited control over particle size. Any attempt to achieve particle size control by thermally driven preparation protocols did not give any satisfying results. However, recent investigations have shown that unprotected NPs can also be synthesized using photochemical methods. This so far unexplored potential for controlling the synthesis of unprotected NPs shall be investigated within the proposed project in order to achieve an appropriate particle size control. Such a synthesis protocol will ultimately enable for investigating systematically and independently the influence of the catalytically relevant material properties (particle size, loading, and support).For fuel cells different degradation mechanisms have been identified. The dependence of these mechanisms on the particle size and particle loading of the catalyst has however still not been determined. Therefore, the second part of the project will focus on this topic by using the previously developed synthesis protocol. Model catalysts will be prepared by deposition of the NPs onto TEM grid carbon films. Furthermore, the application of STEM (scanning transmission electron microscopy) as an experimental tool is planned in order to establish an automated, fast method for performing particle size analyses. In contrast to the established methodology of IL-TEM (identical location transmission electron microscopy) the use of STEM enables not merely for local analysis but also for investigating larger areas within a reasonable time frame. This will perspectively allow not merely for qualitative but also quantitative conclusions regarding the relevance of individual degradation mechanisms.

直接使用氢气作为能源载体是从核能和化石燃料转向可再生能源的一种可能方案。因此，燃料电池技术具有重要的相关性，优化活性和稳定性是促进其适用性的关键挑战。虽然过去人们对催化剂的催化活性进行了较为深入的研究，并开发了活性材料，但对催化剂性能与稳定性之间的关系的了解仍然很少。拟议项目的主要目标是建立一个制备平台，以便系统地研究最相关的催化剂属性(颗粒大小、负载量和载体)对性能的影响，从而也就是催化剂的稳定性。对于最先进的燃料电池催化剂(碳支撑的铂纳米颗粒)来说，这一任务基本上可以使用所谓的无保护铂纳米颗粒(NPs)来解决。这种纳米粒子在碱性乙二醇中被合成为胶体。进一步的制备步骤的应用使得能够将这些颗粒沉积到每种类型的载体材料上。因此，载体和颗粒负载可以独立控制。然而，由于对粒子大小的控制有限，无保护纳米粒子的应用仍然受到阻碍。任何通过热驱动制备方案实现粒度控制的尝试都没有给出任何令人满意的结果。然而，最近的研究表明，也可以用光化学方法合成无保护的纳米粒子。这一迄今尚未开发的控制无保护核子粒合成的潜力应在拟议的项目中进行调查，以便实现适当的粒度控制。这样的合成方案将最终能够系统地和独立地研究催化相关材料性质(颗粒大小、负载和载体)的影响。对于燃料电池，不同的降解机制已经被识别。然而，这些机理与催化剂的颗粒大小和颗粒负载量的依赖关系仍未确定。因此，该项目的第二部分将通过使用先前开发的合成议定书来侧重于这一主题。模型催化剂的制备方法是将纳米粒子沉积在透射电子显微镜栅格碳膜上。此外，计划应用STEM(扫描电子显微镜)作为实验工具，以建立一种自动、快速的粒度分析方法。与已建立的IL-TEM(相同位置透射电子显微镜)方法相比，STEM的使用不仅能够进行局部分析，而且能够在合理的时间框架内调查更大范围的区域。这将使人们不仅可以就个别退化机制的相关性得出定性的结论，而且还可以得出定量的结论。