Proton exchange membrane fuel cells (PEMFCs) should further reduce the platinum consumption to lower their manufacturing costs and life-cycle carbon emissions. However, the performance of the catalyst layers with low-Pt loading needs to be improved. Short-side-chain (SSC) ionomers have been proven to enhance the catalytic activity of conventional catalyst layers. In this work, the SSC ionomer was applied to the electrospun catalyst layer, and achieved a remarkable improvement in the performance. With the use of commercially available catalyst, the membrane electrode assemblies (MEAs) prepared in this work exhibited a low total-Pt-consumption of 0.064 g kW (stoichiometric ratios of 1.5/2.5 for H/air, 80°C, 100 kPa) and achieved the 2025 target proposed by the US Department of Energy. Separating activation, ohmic, and concentration overpotentials, the performance enhancement of the electrospun catalyst layer mainly came from the decrease of ohmic overpotential and concentration overpotential. The electrospun ionomer membrane without catalyst was used as a research model to explore the proton transport properties inside the electrospun catalyst layer. The results showed that in the range of PEMFC operating temperature, the proton conductivity of the electrospun catalyst layer could be higher, but meanwhile the proton-conduction activation energy was also elevated. Compared with the conventional catalyst layer, the electrospun catalyst layer showed obviously better performance before and after accelerated stress test, thus verifying the practicality of the electrospun catalyst layers. This work provided a reference for the development of low platinum and high performance catalyst layers.

中文翻译：

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使用短侧链离聚物的静电纺丝催化剂层，用于低铂和高性能 PEMFC

质子交换膜燃料电池（PEMFC）应进一步减少铂消耗，以降低其制造成本和生命周期碳排放。然而，低Pt负载量的催化剂层的性能需要改进。短侧链（SSC）离聚物已被证明可以增强传统催化剂层的催化活性。本工作将SSC离聚物应用于电纺催化剂层，取得了性能的显着提升。通过使用市售催化剂，本研究制备的膜电极组件 (MEA) 的铂总消耗量较低，为 0.064 g kW（H/空气化学计量比为 1.5/2.5，80°C，100 kPa）并实现了美国能源部提出的2025年目标。分开活化、欧姆和浓度过电势，电纺催化剂层的性能增强主要来自于欧姆过电势和浓度过电势的降低。以不含催化剂的电纺离聚物膜作为研究模型，探索电纺催化剂层内的质子传输特性。结果表明，在PEMFC工作温度范围内，电纺催化剂层的质子电导率较高，但同时质子传导活化能也有所升高。与传统催化剂层相比，静电纺丝催化剂层在加速应力测试前后表现出明显更好的性能，从而验证了静电纺丝催化剂层的实用性。该工作为低铂高性能催化剂层的开发提供了参考。