NSERC-DFG SUSTAIN: In-operando Visualization of catalyst ion transport in PEM fuel cells and electrolyzers

NSERC-DFG SUSTAIN：PEM 燃料电池和电解槽中催化剂离子传输的操作中可视化

• 批准号: 534254124
• 负责人: Professor Dr.-Ing. John Linkhorst
• 金额: --
• 依托单位: Lehrstuhl für Chemische Verfahrenstechnik (CVT)
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/534254124?language=en
• 关键词: NSERC; DFG; SUSTAIN; operando; Visualization

To meet increasing energy demands in an environmentally sustainable manner, Germany and Canada have recognized hydrogen as one of the most promising pathways for decarbonizing the energy sector. Polymer-electrolyte membrane (PEM) fuel cells and PEM electrolyzers are key technologies in this hydrogen economy. For the large-scale adoption of these technologies, an enhancement in stable long-term operation and a reduction in cost is necessary. The two weak links controlling durable operations are catalyst leaching and PEM degradation. Degradation and leaching of catalyst ions negatively impact the electrochemically active area of the catalyst, reducing the overall reaction rate and resulting in performance loss. More specifically, the movement of catalyst metal ions from the catalyst layer into the PEM, as well as their re-deposition, is understood to be of critical importance but is poorly described. The phenomena are strongly influenced by hydration distribution in the PEM. Additionally, the use of environmentally harmful fluorocarbon-based membranes in fuel cells and electrolyzers is currently questioned, and novel hydrocarbon-based membranes are expected to replace them. In this project, we aim to characterize the dynamics of both water and ion transport in poly-electrolyte membranes on different length scales. To gain insights into the factors controlling fuel cells and electrolyzers´ durability, the proposed project combines novel experimental techniques, such as in-operando visualization and ex-situ and post-mortem membrane characterization, with numerical simulations. A microfluidic model system will be employed to study transport phenomena at the microscale. A larger cell, comprising identical membrane and electrode material as classical laboratory-scale setups, will provide insights into the effects of hydration level and act as a bridge between microfluidics and the bench-top scale. In bench-top cells, both conventional fluorocarbon and novel hydrocarbon PEM will be tested to compare electrochemical performance, PEM hydration, and catalyst and membrane degradation. Additionally, simulations will aid in the comparison and interpretation of microscale and macroscale results. For in-situ characterization of water and ion transport in the microfluidic cells, mainly fluorescence-based imaging methods will be used. For the benchtop scale, more traditional methods for membrane and cell characterization will be employed, including water uptake and proton conductivity measurements for the membrane, as well as electron microscopy and elemental analysis of membrane-electrode assemblies. By understanding the fundamentals of transport processes at micro and macro scales, our proposed novel experiments will directly contribute to the design and development of new materials and the identification of perational strategies to mitigate the degradation of PEM fuel cells and electrolyzers.

为了满足以环境可持续性的方式满足能源需求的增加，德国和加拿大已将氢成为脱碳能源部门最有前途的途径之一。聚合物 - 电解质膜（PEM）燃料电池和PEM电解液是这种氢经济的关键技术。对于这些技术的大规模采用，必须提高稳定的长期运行和降低成本。控制耐用操作的两个弱环节是催化剂领先和PEM降解。催化剂离子的降解和行走对催化剂的电化学活性面积产生负面影响，从而降低了总体反应率并导致性能损失。更具体地说，催化剂金属离子从催化剂层转移到PEM及其重新沉积是至关重要的，但描述很差。该现象受PEM中水合分布的强烈影响。此外，目前质疑在燃料电池和电解液中使用环境有害的碳基膜，预计新型碳氢化合物的膜将取代它们。在这个项目中，我们旨在表征不同长度尺度上多性电解质膜中水和离子转运的动力学。为了洞悉控制燃料电池和电解器耐用性的因素，该项目结合了新型的实验技术，例如Operando Introlanization以及Ex-Situ和验尸后膜表征，以及数值模拟。将采用微流体模型系统来研究微观的运输现象。一个较大的细胞，符合性的相同膜和电极材料与经典实验室规模的设置，将为水合水平的影响提供见解，并充当微流体和台式尺度之间的桥梁。常规氟化合物和新型碳氢化合物PEM的细胞将进行测试，以比较电化学性能，PEM水合以及催化剂和膜降解。此外，模拟将有助于比较和解释微观和宏观结果。为了在微流体细胞中水和离子转运的原位表征，将主要使用基于荧光的成像方法。对于台式尺度，将采用更传统的膜和细胞表征方法，包括膜的水吸收和质子电导率测量，以及电子显微镜和膜电极组件的元素分析。通过了解微观和宏观尺度上的运输过程的基本原理，我们提出的新型实验将直接有助于新材料的设计和开发，并鉴定有效策略来减轻PEM燃料电池和电解器的降解。