Degradation and Stabilization of Ionomeric Membranes used in Fuel Cells: Focus on Early Fragmentation Events and Diffusion Processes

技术概述：将应用傅里叶变换红外（FTIR）光谱、ESRI成像（ESRI）和计算方法来详细阐述燃料电池中离子膜的降解和稳定机制。今后四年的主要目标是：从？原位燃料电池的ESR ？?原位燃料电池的ESR成像？将原位实验与ESR成像方法相结合。这种方法将使测量氮氧化物自旋探针和自旋加合物在燃料电池阳极和阴极之间的扩散速率成为可能，从而使交叉过程可视化。2. 通过评估和比较各种中和阳离子对离子单体膜稳定性的影响，重点关注膜的稳定性。3. 以环糊精和葫芦醛为寄主，在疏水环境中包封，增加不稳定中间体的寿命。4. 启动密度泛函理论计算，以了解自由基碎片和加合物的构象对其磁性参数（超细分裂和g值）的影响。与3M、福特实验室和通用汽车电化学能源研究实验室的科学家和工程师的合作，以及国际参与者的贡献，将有助于拟议项目的成功。燃料电池是一种很有前途的清洁能源，可用于汽车和固定设备。聚合物膜对燃料电池的运行至关重要，但其耐久性是燃料电池投入使用之前必须解决的一个主要问题。本提案描述了光谱、成像和计算方法的应用，这些方法有望为燃料电池膜的降解和稳定提供重要的细节。底特律小组与来自3M、福特实验室和通用汽车电化学能源研究实验室的科学家和工程师的合作是转化研究的一个例子：对膜降解机制的基础研究将导致合成更坚固的膜。国际合作将为当地团体增加人才。该研究员将共同教授一门名为？燃料电池基础？该课程将为因当前经济问题而失业的工程师和科学家量身定制，这些工程师和科学家需要接受再培训，以参与“绿色发展”。生产清洁能源的方法。

TECHNICAL SUMMARYESR and Fourier transform infrared (FTIR) spectroscopies, ESR imaging (ESRI) and computational methods will be applied in order to provide details on and formulate the mechanism of degradation and stabilization of ionomer membranes used in fuel cells. The major objectives for the next four years are to: 1. Make the transition from ?ESR in an in situ fuel cell? to ?ESR Imaging of an in situ fuel cell? by combining in situ experiments with the ESR Imaging methods developed in the previous grant period. This approach will make possible measurements of the diffusion rate of nitroxide spin probes and spin adducts between the anode and cathode sides of the fuel cell and thus visualize crossover processes. 2. Focus on membrane stabilization by assessing and comparing the effect of various neutralizing cations on the stability of ionomeric membranes. 3. Increase the lifetimes of unstable intermediates by encapsulation in the hydrophobic environment of cyclodextrins and cucurbiturils as hosts. 4. Initiate density functional theory calculations in order to understand the effect of conformations of radical fragments and adducts on their magnetic parameters (hyperfine splittings and g values). The collaboration with scientists and engineers from 3M, Ford Laboratories, and the General Motors Electrochemical Energy Research Lab, as well as the contributions of international participants, will contribute to the success of the proposed project. NON-TECHNICAL SUMMARYFuel cells are a promising source of clean energy for automotive and stationary applications. Polymer membranes are crucial for fuel cell operation, but their durability is a major problem that must be solved before the fuel cells are in use. This proposal describes the application of spectroscopic, imaging and computational methods that are expected to provide important details on the degradation and stabilization of membranes in fuel cells. The collaboration of the Detroit group with scientists and engineers from 3M, Ford Laboratories, and the General Motors Electrochemical Energy Research Lab is an example of Translational Research: Fundamental studies on the mechanism of membrane degradation will lead to the synthesis of more robust membranes. International collaborations will add talent to the local group. This investigator will co-teach a course entitled ?Fundamentals of Fuel Cells?; the course will be tailored for engineers and scientists who lost their jobs due to the current economic problems and need to be retrained so as to participate in ?green? ways to generate clean energy.