Structure Dependence in the Oxygen Reduction Reaction Electrocatalyzed by Well-Defined Graphene Nanostructures

该项目研究了氮掺杂石墨烯纳米结构（称为石墨烯量子点或GQD）的详细设计，以使其有可能用作燃料电池中铂基电极的低成本替代品。 该研究将提供碳材料的结构如何决定其作为燃料电池应用中重要的氧还原反应（ORR）催化剂的基本理解。 更广泛地说，这项工作将为改进的碳催化剂提供设计指导，从而导致碳材料在环境和能源相关应用中的可再生用途，同时为研究生和本科生提供各种教育机会。 作为有史以来为数不多的定义明确的碳纳米结构之一，GQD为研究碳催化中的结构依赖性提供了独特的机会，而没有传统制备的石墨碳催化剂的复杂性。具体而言，目的是研究杂原子掺杂剂和GQD的尺寸如何影响ORR活性。严格控制的溶液化学将用于制备各种尺寸的GQD，其将用含N或O的物质选择性地官能化。 通过这种方式，与石墨烯的功能化和边缘结构相关的电化学现象将被识别并用作测试理论预测的基础。 纳米石墨烯的高溶解度提供了一个独特的机会来研究它们的内在性质，特别是它们的氧活化电位和相关的电子转移机制，而不受聚集或支撑结构的影响。拟议的研究的跨学科性质将作为一个很好的招聘和培训平台，为研究生和本科生。 对代表性不足的群体的宣传将包括一个夏季研究经验计划，该计划将与Prairie View A M大学合作，目标是来自这所历史上的黑人大学的本科生。

The project investigates the detailed design of nitrogen-doped graphene nanostructures (known as graphene quantum dots, or GQDs) for their potential use as low-cost replacements for platinum-based electrodes in fuel cells. The study will provide basic understanding of how the structures of carbon materials determine their roles as catalysts for the important oxygen reduction reaction (ORR) in fuel cell applications. More broadly, the work will provide design guidance for improved carbon catalysts, thereby leading to renewable uses of carbon materials for environment- and energy-related applications, while providing a diverse range of educational opportunities for graduate and undergraduate students. As one of the few well-defined carbon nanostructures ever made, the GQDs offer unique opportunities for studying the structure dependence in carbon catalysis, without the complexity of conventionally-prepared graphitic carbon catalysts. Specifically, the aim is to investigate how heteroatom dopants and sizes of the GQDs affect the ORR activities. Tightly-controlled solution chemistry will be used to prepare GQDs of various sizes which will be selectively functionalized with N- or O-containing species. In this way, electrocehemical phenomena associated with both the functionalization and edge structures of the graphenes will be identified and used as a basis for testing theoretical predictions. The high solubility of the nanographenes offers a unique opportunity to study their intrinsic properties, especially their oxygen-activating potential and associated electron transfer mechanism, without being affected by aggregation or supporting structures. The interdisciplinary nature of the proposed research will serve as an excellent recruiting and training platform for both graduate and undergraduate students. Outreach to underrepresented groups will include a summer research experience program with Prairie View A&M University targeting undergraduate students from that historically black university.