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，以期将其用作燃料电池中铂电极的低成本替代品。这项研究将对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)的催化剂的作用提供基本的理解。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利用，同时为研究生和本科生提供各种教育机会。作为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，而不像传统制备的石墨碳催化剂那样复杂。具体地说，目的是研究杂原子掺杂剂和GQD的尺寸对ORR活性的影响。严格控制的溶液化学将被用来制备不同尺寸的GQD，这些GQD将被选择性地与含N或O的物种官能化。这样，与石墨烯的官能化和边缘结构相关的电化学现象将被识别并用作检验理论预测的基础。拟议研究的跨学科性质将为研究生和本科生提供一个极好的招聘和培训平台。面向代表性不足的群体，将包括与Prairie View A&Amp；M大学合作的暑期研究体验项目，目标是来自这所历史悠久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.