Thoi Research Group

  • Using Molecular Interactions 
in Materials Development for Energy Solutions
  • Tuning Chemical Environments in Catalysis for Mechanistic Insights

Current Projects

Metal Organic Frameworks for Energy Storage Devices

Derived from the self-assembly of metal ions and organic linkers, MOFs are promising materials for devices such as fuel cells and batteries due to their intrinsic high surface area, periodicity, and thermal stability. However, most MOFs exhibit low conductivity, owing to the poor orbital overlap between the metal ion and the ligand. We apply chemical design principles such as the use of more covalent metal-linker bonds, pi-pi interactions, and host-guest chemistry to understand and promote electron transport. Using experimental data and calculations, we also use MOFs for enhancing the energy density and the lifetime performance of lithium sulfur batteries. We take advantage of the synthetic modularity of MOFs to install anchoring sites for polysulfides, which can prevent sulfide leaching and lower the energetic barrier for cycling. Moreover, the rich host-guest chemistry and high crystallinity of MOFs offer molecular models for elucidating cycling mechanism that is difficult to obtain in conventional electrode materials.

Engineering Interfacial and Catalytic Sites for Small Molecule Activation

We develop solid state and molecular electrocatalysts to utilize renewable solar energy and electricity for energy conversion and environmental applications. Our goal is to understand the complex interactions occurring at the solid-liquid-gas interfaces during catalysis. We tune the properties of our porous substrates such as surface area, porosity, chemical composition, and mesostructure to probe the solution dynamics. For instance, we aim to understand the relationship between substrate properties and catalytic CO2 reduction activity by systematically tuning the carbon aerogel, a porous carbon foam composed of graphitic sheets, and determining product distributions and yields. Other projects include studying earth-abundant metal complexes for NOx reduction, employing organic additives to tune electrochemical interfaces, and developing novel porous metal-organic materials and metal alloys for carbon and nitrogen activation