Hyunho Noh

Assistant Professor

Research Areas: Inorganic, Materials
Email: Hyunho.Noh-1@ou.edu
Office: SLSRC 3310

Education:
B.S., 2014, University of Illinois Urbana-Champaign
Ph.D., 2019, Northwestern University
Postdoc, 2019-2023, Yale University

Research Keywords:
Electrochemistry, Electrocatalysis, Metal−Organic Framework, Heterogeneous Catalysis

Research Overview:

The demand to shift the energy sector towards more carbon-neutral, renewable energy sources prompts the need to develop efficient heterogeneous catalysts that can convert solar energy into chemical fuels. Designing efficient catalysts requires the exact understanding and correlation of the structure, thermodynamics, and kinetics at the catalyst-solution interfaces to further establish catalyst design principles. These can direct chemists, material scientists, and engineers toward the next-generation heterogeneous catalysts for a net carbon-neutral and sustainable economy.

Research in our group focuses on achieving molecular-level understanding and control of the heterogeneous electrocatalyst structure and the surrounding environment using model systems. By examining how each structural components influence the interfacial thermodynamics and kinetics, structure-thermodynamics-activity relationships for electrocatalysts relevant to sustainable energy generation can be established. Our group will achieve this by employing porous and crystalline metal−organic frameworks (MOFs) and transition metal nitrides.

Structure-Thermochemistry-Activity Relationships of MOF-based Electrocatalysts

The adsorption energy of catalytically relevant intermediates lays the foundation of heterogeneous catalyst design principles as it correlates with the reaction rate. Yet, the exact interfacial structure of conventional heterogeneous catalysts remains ambiguous. This further hampers an understanding of how the catalyst structure and the surrounding environment can be tailored for optimal performance. Using the structural explicitness and modularity of MOFs to our advantage, our group uses redox active MOFs as candidate electrocatalysts to directly measure catalytically relevant binding energies. Systematic modulation of the local and the extended lattice structure will assess how these can be harnessed to our advantage in yielding optimal binding energy, and therefore high catalytic performance.

Microenvironment Control at the Electrode-Electrolyte Interfaces using MOFs

The arrangement of solvated ions and solvent molecules at the electrode-electrolyte interfaces alters catalytically relevant thermodynamics and kinetics. Precise structural control of the electrochemical double layer allows a molecular-level understanding of how to tailor the microenvironment for enhanced catalytic activity and selectivity. Here, our group uses chemically tunable MOFs that enable control of the identity, density, and orientation of functional groups to define the physical and chemical environment within the pores. MOFs will be established as structure-directing agents for various energy-relevant transformations such as the hydrogen evolution reaction, CO₂ reduction reactions, and many others.

Transition Metal Nitride-Catalyzed Dinitrogen Electro-Reduction

The Haber-Bosch process is an energy-intensive, thermal process that supports much of the modern-day ammonia synthesis for fertilizers and many other purposes. Electrochemical N₂ reduction reaction (NRR) to ammonia at benign applied potentials is an attractive alternative as it does not require high pressure/temperature. Our group focuses on transition metal nitrides, which have computationally exhibited promisingly high activity and selectivity as candidate NRR electrocatalysts. Through systematic modification of the interfacial structure, we aim to understand how these structural changes impact the thermodynamics of elementary steps in the N₂ electro-reduction catalytic cycle, and consequently, the overall reaction rate and selectivity. These studies should lead to design principles of transition metal nitrides for N₂ reduction that remains rare in the literature.

Group Website