CAS: Collaborative Research: Design, Characterization, and Modeling of Metal Nanocluster Electrocatalysts Linked to Three-Dimensional Graphene

With support of the Chemical Structure, Dynamics & Mechanisms-B Program of the Division of Chemistry, Kwok-Fan Chow, Jerome Delhommelle, and Mingdi Yan of the Department of Chemistry at the University of Massachusetts Lowell and Gonghu Li of the Department of Chemistry at the University of New Hampshire are developing new classes of graphene-supported nanocomposite materials for electrocatalytic applications. The goal of this research is to develop a new strategy for constructing electrocatalysts from metal nanoclusters (MNCs) and pristine graphene for electrochemical CO2 reduction. Knowledge gained through the proposed research is expected to improve our fundamental understanding of how the solid-solid interface impacts the electrocatalytic properties of nanocomposites. Such understanding could guide the design and fabrication of innovative devices for renewable energy applications. This project will provide excellent training opportunities for undergraduate and graduate researchers, promoting the participation of women and underrepresented minorities in STEM (science, technology, engineering and mathematics) research. This project also includes outreach activities (multiple one-day workshops at both institutions) designed for K-12 students to increase the national talent pipeline in nanoscience, chemistry, and materials science disciplines. Graphene-supported nanocomposite materials have attracted increasing interest among researchers due to their potential applications in various areas including catalysis. However, in graphene-based nanocomposite catalysts, the solid-solid interfaces between catalysts and graphene are often poorly defined. Understanding and optimizing such interfaces is particularly important for electrocatalytic applications such as CO2 reduction, in which electrons need to migrate from the graphene electrode to the catalyst. Molecular functionalization of graphene offers enormous opportunities to prepare new electrocatalysts (particularly MNCs) with enhanced electron transfer kinetics. Using gold nanoclusters (AuNCs) as the model MNCs, this project aims to develop a new strategy for constructing innovative electrocatalysts from MNCs and pristine graphene. Specifically, AuNCs will be covalently attached onto three-dimensional pristine graphene (3DG) electrodes through a series of rationally designed molecular linkers. This project requires complementary expertise from four research groups. A combination of synthesis, computational modeling, electrochemistry, and spectroscopy will be employed to investigate how the linker structure affects the performance of the AuNC-3DG electrocatalytic CO2 reduction. It is anticipated that the results obtained will enhance our fundamental understanding of how control over solid-solid interfaces at the molecular level impacts the performance of nanocomposite materials in electrochemical devices. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.