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。如果成功的话，实用的燃料电池将成为转向绿色经济的关键技术。然而，燃料电池的成功应用受到与氧还原反应动力学相关的因素的阻碍。似乎需要昂贵的铂基催化剂来催化这些氧还原反应。铂当然是稀有和昂贵的，并且容易被一氧化碳等分子中毒，导致催化剂寿命缩短。尽管进行了数十年的研究，但很少发现具有有希望的氧还原催化活性的非贵金属催化剂，并且没有一种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Xianqin Wang和Zafar Iqbal提出了一种完全不同的新阴极材料方法。理论上预测聚合氮是一种高能量密度材料。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，聚合物氮相可以在碳纳米管内的环境条件下稳定。碳纳米管中聚合氮的带隙计算表明，所有链长的低聚物是半导体的。因此，碳纳米管中聚合氮的成功合成提供了确认这种材料在燃料电池应用中的可行性的机会。此外，这些材料可以作为其他反应的催化剂进行评估。EAGER的建议将为PI提供扩展一些初步发现的机会。PI已经在使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，并且已经证明在碳纳米管基底上具有一定的稳定性。这些都是非常初步的成功。EAGER的实验任务包括：合成稳定在碳纳米管片上的聚合物氮，测定材料的性质和稳定性，使用改进的当前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，并与市售的铂碳阴极进行比较。成功的性能证明将导致进一步的表征研究以及稳定性测定。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增量研究截然不同。成功可能是非常有价值的。即使在燃料电池催化中不成功，该合成也为其他反应提供了新的催化剂潜力。 在教育方向方面，这两个PI将指导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挑战性的项目。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.