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GQDs）的详细设计，以作为燃料电池中铂基电极的低成本替代品。这项研究将提供对碳材料的结构如何决定它们在燃料电池应用中作为重要氧还原反应（ORR）催化剂的作用的基本理解。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使用，同时为研究生和本科生提供各种各样的教育机会。作为为数不多的定义明确的碳纳米结构之一，GQDs为研究碳催化中的结构依赖性提供了独特的机会，而没有传统制备石墨碳催化剂的复杂性。具体来说，目的是研究杂原子掺杂剂和GQDs的大小如何影响ORR活性。严格控制的溶液化学将用于制备各种尺寸的GQDs，这些GQDs将选择性地与含N或含o的物质功能化。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其内在性质，特别是它们的氧活化电位和相关的电子转移机制，而不受聚集或支持结构的影响。拟议研究的跨学科性质将为研究生和本科生提供一个优秀的招聘和培训平台。向代表性不足的群体伸出援手的项目包括与Prairie View A&amp；M大学合作，针对这所历史悠久的黑人大学的本科生开展暑期研究体验项目。

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.