SGER: Novel Organic-Inorganic Hybrid Fuel Cell Membranes

CBET-0833837Zhang本研究的目的是探索利用表面引发原子转移自由基聚合(SI-ATRP)和静电纺丝技术来创造一种新型的混合燃料电池膜。燃料电池有望成为清洁能源的候选者。发电，因为它们提供的电力不会燃烧，也不会产生与燃烧化石燃料相关的污染物。目前的PEMFC技术使用Nafion®膜将燃料从氧化剂中分离出来，并将质子从阳极输送到阴极。然而，Nafion®存在工作温度低、磺酸含量有限、在低相对湿度下质子传导性差、机械稳定性不足以及成本高等问题。该工作提出了一种新型的有机-无机杂化膜的合成方法，利用SI-ATRP技术直接在电纺SZrO2纳米纤维多孔骨架的非织造孔中生成超高密度、超长的功能聚合物。这些杂化膜还将与新型催化层集成，以实现高燃料电池性能。还是？控制？自由基聚合，可以实现定义明确的高密度聚合物链，在固体表面具有极大的相对分子质量和低的多分散性。电纺S-二氧化锆纳米纤维即使在高温(150oC)和低湿度下也具有高导电性，并可以形成多孔无纺布骨架，为附着具有前所未有的磺酸含量的聚合物提供出色的机械支撑，同时仍保持良好的尺寸稳定性。除了S-氧化锆骨架的高电导率外，这种方法获得的超高含量的紧密缔合酸基可以提供大量的？进一步提高了质子膜的性能。由此得到的杂化膜具有高质子导电率、提高工作温度极限、良好的机械强度、较长的工作寿命和较低的成本等优点，因此它们可以显著提高燃料电池系统的性能。为制备具有明确结构和多功能的纳米纤维基多孔无机和有机-无机杂化膜奠定了基础。燃料电池技术的研究也将得到推进，这将减少对国外石油的依赖，改善空气质量，减少温室气体排放。这些与能源相关的新型材料和系统的研究和教育活动将帮助美国在这些战略领域保持领先地位。

CBET-0833837ZhangThe objective of this research is to explore the use of surface-initiated atom transfer radical polymerization (SI-ATRP) and electrospinning technologies to create a novel type of hybrid fuel cell membrane. Fuel cells are promising candidates for ?clean? power generation because they provide electricity without combustion and pollutants associated with burning fossil fuels. Current PEMFC technologies use Nafion® membranes to separate the fuel from the oxidant and transport protons from the anode to the cathode. However, Nafion® suffers from problems including low operating temperature, limited sulfonic acid content, poor proton conductivity at low relative humidity, insufficient mechanical stability, and high cost. The work proposes to synthesize a novel type of organic-inorganic hybrid membrane by using SI-ATRP technology to generate extra-high density, ultra-long functional polymers directly in the nonwoven pores of electrospun SZrO2 nanofiber-based porous frameworks. These hybrid membranes will also be integrated with novel catalyst layers to achieve high fuel cell performance.Intellectual merit: SI-ATRP is a recently developed technology of ?living? or ?controlled? radical polymerization that can realize well-defined, high-density polymer chains with exceptionally large molecular weights and low polydispersities on solid surfaces. Electrospun S-ZrO2 nanofibers have high conductivities even at high temperatures ( 150oC) and low humidities, and can form a porous nonwoven framework to provide excellent mechanical support for attaching polymers with unprecedented sulfonic-acid content while still maintaining good dimensional stability. In addition to the high conductivity of the S-ZrO2 frameworks, the extra-high content of closely-associated acid groups achieved by this method can provide a large amount of ?free? protons to further enhance the membrane performance. The resultant hybrid membranes have advantages of high proton conductivity, increased operating temperature limit, good mechanical strength, long operational life, and low cost, and hence they can significantly improve the performance of fuel cell systems.Broader impacts: The results of this proposed research are expected to have important scientific and economic impacts. Foundation for fabricating nanofiber-based porous inorganic and organic-inorganic hybrid membranes with well-defined structures and multi-functionalities will be established. Research of fuel cell technologies, which will reduce our foreign oil dependence, improve air quality, and reduce greenhouse gas emissions, will also be advanced. These research and education activities in novel energy-related materials and systems will help the U.S. stay in a lead position in these strategic fields.