EAGER: Investigation of Polymeric Nitrogen Supported on Carbon Nanotube Sheets for Oxygen Reduction in Fuel Cells

燃料电池是通过电化学反应将燃料的化学能直接转化为电能的装置。如果获得成功，实用的燃料电池将成为推动绿色经济发展的关键技术。然而，燃料电池的成功应用一直受到与氧还原反应动力学有关的因素的阻碍。昂贵的铂基催化剂似乎需要催化这些氧还原反应。铂当然是稀有和昂贵的，并且容易受到一氧化碳等分子的毒害，导致催化剂寿命缩短。经过几十年的研究，发现具有良好氧还原催化活性的非贵金属催化剂很少，而且没有一种催化剂表现出足够的性能稳定性。来自新泽西州纽瓦克的新泽西理工学院的研究人员王仙琴和扎法伊克巴尔提出了一种完全不同的方法来制造一种新的阴极材料。高分子氮在理论上被预测为一种高能量密度的材料。已经考虑了各种模式来稳定这种材料。从头算分子动力学模拟预测了碳纳米管内部的聚合氮相可以在环境条件下稳定。碳纳米管中聚氮的带隙计算表明，低聚物的所有链长都是半导体的。因此，碳纳米管中聚合氮的成功合成为确认这种材料在燃料电池应用中的可行性提供了机会。此外，这些材料还可以作为其他反应的催化剂。该EAGER提案将为pi提供扩展一些初步发现的机会。这些pi已经在利用电化学和等离子体聚合方法合成聚合氮方面取得了初步成功，并且在碳纳米管衬底上表现出一定的稳定性。这些都是非常初步的成功。在这个EAGER提案中的实验任务包括：合成稳定在碳纳米管片上的聚合物氮，确定材料的性质和稳定性，使用改进的现有商业技术制造聚合物氮基阴极，测量该阴极在氧还原反应中的性能，并与市售的碳上铂阴极进行比较。成功的性能演示将导致进一步的表征研究以及稳定性的确定。更广泛的影响：几十年来，燃料电池中铂催化剂的问题一直是限制因素。这种方法与该领域的许多其他渐进式研究截然不同。成功可能是非常宝贵的。即使在燃料电池催化中没有成功，合成也为其他反应提供了新的催化剂潜力。在教育方向上，两位pi将指导一名研究生在一年内完成这些初步实验。这对学生来说将是一个具有挑战性的课题。此外，新催化剂技术的潜力将增加教育价值。

Fuel cells are devices for direct conversion of the chemical energy of a fuel into electricity through electrochemical reactions. If successful, practical fuel cells would be a key enabling technology for movement to a green economy. However successful application of fuel cells has been hindered by factors relating to the kinetics of the oxygen reduction reaction. Expensive platinum-based catalysts seem to be required to catalyze these oxygen reduction reactions. Platinum is of course rare and expensive and is susceptible to poisoning by molecules such as carbon monoxide, leading to reduced catalyst lifetimes. Despite many decades of research, very few non-precious metal catalysts have been found with promising oxygen reduction catalytic activity and none have exhibited sufficient performance stability. Investigators Xianqin Wang and Zafar Iqbal from New Jersey Institute of Technology, Newark, NJ, are proposing a radically different approach to a new cathode material. Polymeric nitrogen has been theoretically predicted to be a high energy-density material. Various modes have been considered for stabilization of this material. Ab initio molecular dynamic simulations have predicted that a polymeric nitrogen phase can be stabilized at ambient conditions inside carbon nanotubes. Calculation of band gaps for polymeric nitrogen in carbon nanotubes indicates all chain lengths of oligomers are semiconducting. Thus, successful synthesis of polymeric nitrogen in carbon nanotubes offers the opportunity to confirm the viability of such a material in a fuel-cell application. In addition, such materials could be evaluated as catalysts for other reactions.This EAGER proposal will offer the PIs the opportunity to expand on some initial findings. The PIs have had preliminary success in the synthesis of polymeric nitrogen using electrochemical and plasma polymerization approaches and have demonstrated some stabilization on a carbon nanotube substrate. These are very preliminary successes. Experimental tasks in this EAGER proposal include: synthesis of polymeric nitrogen stabilized on carbon nanotube sheets, determination of properties and stability of the materials, fabrication of a polymeric nitrogen-based cathode using modified current commercial techniques, measurement of the performance of this cathode in the oxygen reduction reaction and comparison to a commercially available platinum-on- carbon cathode. Successful performance demonstration will lead to further characterization studies as well as determination of stability. Broader Impacts:The issues with platinum catalysts in fuel cells have been limiting factors for decades. This approach is radically different than many other incremental studies in the area. Success could be very valuable. Even if not successful in fuel cell catalysis, the synthesis offers new catalyst potential for other reactions. In terms of educational directions, the two PIs will guide a graduate student in the accomplishment of these initial experiments in one year. This will be a challenging project for the student. In addition, the potential of new catalyst technology will add to the educational value.