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

Indiana University, Bloomington IN

Investigators

Abstract

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.