Advanced Graphene Based Non-Precious Catalysts for Fuel Cells

为了满足现代社会不断增长的能源需求，同时解决环境问题，对具有成本效益、可持续和清洁能源技术的需求空前高涨。聚合物电解质膜（PEM）燃料电池因为能够满足这些要求而备受推崇，尤其是在运输应用方面，它们可以显著减少加拿大每年释放到大气中的50多万吨二氧化碳。然而，目前PEM燃料电池仍然过于昂贵，并且没有足够的耐久性，因此不能被认为是传统技术（如内燃机）的经济替代品。铂基催化剂价格昂贵，系统成本高，耐用性差。非贵重催化剂（npc）代表了非常有吸引力的替代品，尽管在生产高活性和操作稳定的材料方面仍然取得了有限的进展，同时对其制造和设备集成产生了基本的理解和知识。石墨烯已成为极有前景的催化剂载体和电极材料，由于其迷人的性能，包括典型的表面积，良好的电子导电性，在PEM燃料电池运行过程中优异的耐蚀性。本提案的目标是通过新技术和独特的三维电极结构开发四种基于石墨烯的npc，这些npc可以在PEM燃料电池工作条件下提供高ORR活性和耐久性。这些NPC材料将进行物理、光谱和电化学表征，以阐明控制催化剂活性和稳定性的潜在因素。这一进展对于未来设计和准备技术上实用的npc至关重要。由此，一些最有前途的石墨烯催化剂将集成到独特的NPC电极设计中，这些电极将在单个PEM燃料电池中制备和研究，以优化电极性能，包括厚度、孔隙度、离子相互作用等。将进行详细的研究，以模拟在电极中发生的传输过程，并优化物理性质和制备参数。最后，预计优化后的NPC电极将进行广泛的性能和耐用性测试，然后进行测试后表征，以阐明长期性能损失的机制途径，并设计和实施缓解策略。这项新颖的研究不仅将在石墨烯基催化剂设计和电极集成方面提供技术和科学进步，这将对材料科学，电化学，催化和能量存储/转换技术（即电池，燃料电池和超级电容器）具有重要意义，而且与传统的Pt基催化剂相比，还将提供巨大的经济优势。并将大大降低燃料电池制造和分销公司的成本。最后，从事这项工作的HQP人员将接受教授、博士后和高级研究生的高质量培训，同时为他们提供最先进的设备，以便成功地开展他们的项目和学位课程。预计这些技术、知识和HQP培训将有利于加拿大能源部门的知识型经济，同时也会引起材料科学家和工程师、化学工程师、纳米技术专家、催化化学家和电化学家的兴趣。

The demand for cost effective, sustainable and clean energy technologies is at an all-time high in order to meet the ever increasing energy demands of modern society while addressing environmental concerns. Polymer electrolyte membrane (PEM) fuel cells are highly touted as they can meet these requirements, considered most notably for transportation applications whereby they can significantly reduce the over 500 thousand tonnes of carbon dioxide released into the atmosphere in Canada each year. Currently however, PEM fuel cells are still too expensive and do not possess sufficient durability to be considered economical alternatives to conventional technologies such as the internal combustion engine. The high system cost and poor durability arises from the expensive platinum (Pt) based catalysts. Non-precious catalysts (NPCs) represent highly attractive alternatives, although still limited progress has been made in terms of producing highly active and operationally stable materials, along with generating fundamental understanding and knowledge regarding their fabrication and device integration.Graphene has emerged as highly promising catalyst support and electrode materials, owing to fascinating properties including exemplary surface areas, good electronic conductivity, excellent corrosion resistivity during PEM fuel cell operation. It is the objective of the present proposal to develop four types of graphene based NPCs by new techniques and unique 3-dimensional electrode architectures that can provide high ORR activity and durability under PEM fuel cell operating conditions. These NPC materials will be characterized physically, spectroscopically and electrochemically in order to elucidate the underlying factors governing catalyst activity and stability. This progress will be fundamentally crucial for the future design and preparation of technologically practical NPCs. From this, some of the most promising graphene catalysts will be integrated into unique NPC electrode designs that will be prepared and investigated in a single cell PEM fuel cell in order to optimize electrode properties including thickness, porosity, ionomer interactions, etc. Detailed investigations will be applied in order to model transport processes occurring in the electrodes and optimize the physical properties and preparation parameters. Finally it is expected that the optimized NPC electrodes will be extensively tested for performance and durability capabilities, and then subjected to post-testing characterization in order to elucidate the mechanistic pathway of long term performance loss and to design and implement mitigation strategies.This novel research will not only provide technical and scientific progress in terms of graphene based catalyst design and electrode integration that will be of high importance to materials science, electrochemistry, catalysis and energy storage/conversion technology (i.e. battery, fuel cell and supercapacitor) but also provide immense economic advantages in comparison to conventional Pt based catalysts, and will bring enormous cost reductions to fuel cell manufacture and distribution companies. Finally, the HQP personnel trained in this work will be exposed to top quality training from professors, postdoctoral fellows and senior graduate students, while being provided access to state of the art equipment in order to successfully carry out their projects and degree programs. It is expected that the technologies, knowledge and HQP trained will benefit the Canadian knowledge based economy in the energy sector, while being of interest to materials scientists and engineers, chemical engineers, nanotechnologists, catalysis chemists and electrochemists.