Proton conducting and hydrophilic coordination polymers - synthesis, spectroscopic investigation and incorporation in fuel cell membranes

质子导电材料是燃料电池的关键部件，燃料电池利用氢和氧来产生电能和热量。目前使用的最先进材料是全氟磺酸离聚体Nafion，但其用途仅限于高湿度值，因此适用于低温(&lt；80°C)。需要能够在较高温度下使用的新功能材料，最好是在无水条件下使用。配位聚合物(CP)是一类非常有前景的化合物，适合于这类应用。该项目的范围是在不同组成的燃料电池复合膜中创建、理解和开发质子导电配位聚合物(PCCP)，并实时在线监测湿度和质子传导性。将特别强调引入-PO3H2或-PO3H-基团和额外的质子载体，以创造具有高和稳定的质子导电性的材料。为了更好地理解CPS的结构-性质关系以及水分子和颗粒大小的作用，我们将详细研究不同相对湿度下的质子传导机制。为了研究它们在燃料电池中的可能应用，将制备包含不同颗粒尺寸的PCCP的复合聚合物膜并进行测试。由于相对湿度对质子传导有很大的影响，因此需要研制一种传感器来实时监测细胞膜在载荷作用下的湿度。为此，我们汇集了诺伯特·斯托克(基尔)、迈克尔·沃克(奥尔登堡)和迈克尔·蒂曼(帕德伯恩)的研究小组，协同结合了他们在配位聚合物的合成/表征、复合膜中的质子传导和传感方面的互补技能。五氯环丙烷将在库存组合成。对于选定的体系，将制定针对颗粒尺寸受控的PCCP纳米颗粒的合成策略。蒂曼团队将进行深入的温度相关阻抗谱研究，以研究质子传导途径，并将制造边缘电场(FEF)传感元件。该传感器元件将有助于在复合膜上进行现场阻抗测量，该复合膜将由沃克小组进行详细的准备和测试。各种含有磺酸盐和膦酸基的聚合物以及酸碱聚合物共混物将被用于形成这种复合膜，此外，将研究由连续的PCCP和聚合物层组成的膜。在与母羊研究所的密切合作下，Next Energy精选复合膜将用于制造膜电极组件。这些将应用于在实际燃料电池条件下运行的试验台。

Proton conducting materials are a key component in fuel cells, which use hydrogen and oxygen to produce electricity and heat. The state-of-the-art material currently employed is the perfluorosulfonic acid ionomer Nafion, but its use is limited to high humidity values and, hence, to low temperatures (< 80 °C). New functional materials that can be used at higher temperatures, preferably under anhydrous conditions, are needed. Coordination polymers (CPs) are one very promising class of compounds suitable for this kind of applications. The scope of this project is the creation, understanding, and exploitation of proton-conducting coordination polymers (PCCPs) in fuel cell composite membranes of various compositions and the real-time in-situ monitoring of humidity and proton conductivity. Special emphasis will be placed on introducing -PO3H2 or -PO3H- groups and additional proton carriers to create materials with a high and stable proton conductivity. To develop a better understanding for the structure-property relationship and the role of water molecules and particle size of the CPs, the proton conducting mechanism under various relative humidity values will be studied in detail. To investigate their possible application in fuel cells, composite polymer membranes which contain PCCPs of various particle sizes will be fabricated and tested. Since the relative humidity has a strong influence on the proton conduction a sensor will be developed to monitor in situ the humidity in the cell membrane under load. To accomplish this, we brought together the research groups of Norbert Stock (Kiel), Michael Wark (Oldenburg), and Michael Tiemann (Paderborn), synergistically combining their complementary skills in synthesis/characterization of coordination polymers, proton conduction in composite membranes, and sensing. The PCCPs will be synthesized in the Stock group. For selected systems synthetic strategies towards PCCP nanoparticles with controlled particle sizes will be established. The Tiemann group will carry out in-depth temperature-dependent impedance spectroscopic investigations to study the proton conduction pathway and will also fabricate a fringing electric field (FEF) sensing element. This sensor element will facilitate in-situ impedance measurements on the composite membranes which will be prepared and tested in detail by the Wark group. Various polymers containing sulfonate and phosphonate groups as well as acid-base polymer blends will be employed in the formation of such composite membranes and, in addition, membranes consisting of consecutive PCCPs and polymer layers will be studied. In close collaboration with the EWE Research Institute NEXT ENERGY selected composite membranes will be used to fabricate membrane-electrode assemblies. These will be applied in a test stand operating at realistic fuel cell conditions.