共查询到10条相似文献,搜索用时 46 毫秒
1.
2.
3.
Holly L. S. Salerno Frederick L. Beyer Yossef A. Elabd 《Journal of Polymer Science.Polymer Physics》2012,50(8):552-562
Robust hydroxide conducting membranes are required for long‐lasting, low‐cost solid alkaline fuel cells (AFCs). In this study, we synthesize Nafion‐based anion exchange membranes (AEMs) via amination of the Nafion precursor membrane with 1,4‐dimethylpiperazine. This initial reaction produces an AEM with covalently attached dimethylpiperazinium cations neutralized with fluoride anions, while a subsequent ion exchange reaction produces a hydroxide ion conducting membrane. These AEMs possess high thermal stability and different thermal transition temperatures compared to Nafion, while small‐angle X‐ray scattering reveals a similar ionic morphology. The hydroxide ion conductivity of the Nafion‐based AEM is fivefold lower than the proton conductivity of Nafion at 80 °C and 90% relative humidity. More importantly, the hydroxide conductivity is insensitive to drying and rehydrating the membrane, which is atypical of other AEMs with quaternary ammonium cations. The high chemical and thermal stability of this hydroxide conducting Nafion‐based AEM provides a promising alternative for AFCs. © 2011 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2011 相似文献
4.
5.
低温燃料电池是理想的移动式电源,它所采用的电催化剂主要为Pt基贵金属纳米催化剂。提高纳米催化剂在电池内部环境中的稳定性、抑制其活性衰减,对于延长低温燃料电池的使用寿命和节约成本具有十分重要的意义。本文从三个方面综述了近年来在低温燃料电池纳米催化剂稳定化方面的研究进展。首先,通过载体效应实现催化剂的稳定化,包括碳载体的石墨化、碳载体的掺杂、表面功能化及其他载体的采用等。其次,通过空间效应实现催化剂的稳定化,包括催化剂粒子表面覆盖、催化剂粒子微孔嵌入、催化剂表面杂多酸单层自组装及聚合物电解质空间阻隔等。再其次,通过协同效应实现催化剂的稳定化,包括提升金属粒子的氧化电位、强化组分间的相互作用等。最后,对低温燃料电池纳米催化剂稳定化的发展前景进行了展望。 相似文献
6.
Confined‐Space Alloying of Nanoparticles for the Synthesis of Efficient PtNi Fuel‐Cell Catalysts 下载免费PDF全文
Claudio Baldizzone Stefano Mezzavilla Dr. Hudson W. P. Carvalho Dr. Josef Christian Meier Dr. Anna K. Schuppert Dr. Marc Heggen Dr. Carolina Galeano Prof. Dr. Jan‐Dierk Grunwaldt Prof. Dr. Ferdi Schüth Dr. Karl J. J. Mayrhofer 《Angewandte Chemie (International ed. in English)》2014,53(51):14250-14254
The efficiency of polymer electrolyte membrane fuel cells is strongly depending on the electrocatalyst performance, that is, its activity and stability. We have designed a catalyst material that combines both, the high activity for the decisive cathodic oxygen reduction reaction associated with nanoscale Pt alloys, and the excellent durability of an advanced nanostructured support. Owing to the high specific activity and large active surface area, the catalyst shows extraordinary mass activity values of 1.0 A mgPt?1. Moreover, the material retains its initial active surface area and intrinsic activity during an extended accelerated aging test within the typical operation range. This excellent performance is achieved by confined‐space alloying of the nanoparticles in a controlled manner in the pores of the support. 相似文献
7.
8.
9.
10.
Dr. Elena Madrid Yuanyang Rong Dr. Mariolino Carta Prof. Neil B. McKeown Richard Malpass‐Evans Prof. Gary A. Attard Tomos J. Clarke Prof. Stuart H. Taylor Prof. Yi‐Tao Long Prof. Frank Marken 《Angewandte Chemie (International ed. in English)》2014,53(40):10751-10754
A highly rigid amine‐based polymer of intrinsic microporosity (PIM), prepared by a polymerization reaction involving the formation of Tröger’s base, is demonstrated to act as an ionic diode with electrolyte‐dependent bistable switchable states. 相似文献