Jinwon Cho

(Advisor: Prof. Seung Soon Jang)

will propose a doctoral thesis entitled,

Development of Novel Platforms for Homogeneous and Heterogeneous Catalysis Toward Sustainable Chemistry:

A Multiscale Modeling Approach

on

Monday, December 4 at 1:30 p.m.

Love 298

and

Virtually via

Microsoft Teams Link

Abstract

Catalysis is used in a wide range of applications, including those involved in producing drugs, bioproducts, and chemical hydrogen storage. The key challenge in catalyst design is achieving high reaction rate, selectivity, and durability across various branches of chemistry. Recent advances in computational chemistry have significantly contributed to the design of the next generation of catalysis by rationalizing experimental observations, elucidating reaction mechanisms, and identifying key descriptors. In this proposal, a multiscale modeling approach was employed to address challenges in both homogenous catalysis for aldol addition reaction and heterogenous catalysis for electrochemical CO2 reduction to formic acid, aiming for sustainable and green chemistry.   

In the first part of research, we have proposed the self-assembled multicompartment micelles (MCMs), formed spontaneously by amphiphilic block copolymers in water solvent, as a nanoreactor for the proline catalyzed aldol addition reaction. Despite the discovery of asymmetric aldol addition reaction more than a century ago, it continues to present challenges in achieving high yields and selectivity in water medium, which is considered as the most environmentally friendly solvent. In this regard, MCMs is used as a support system that encapsulates catalysis in the hydrophobic core, making them suitable for the desired reactions within an aqueous medium. This approach allows the effective confinement and protection of catalytic species within the MCMs, leading to enhanced catalytic performance and selectivity. To design such MCMs, a multiscale computational protocol to calculate the Flory-Huggins 𝜒-parameter, a key factor in predicting the miscibility of polymer-polymer and polymer-solvent mixtures, was first developed. This parameter is then utilized to the prediction of the morphology of MCMs which is often directly influenced by block ratio, sequence, and the location catalysis within the polymer chain. Finally, the aldol addition reaction between acetone and 4-nitrobenzaldyhe was evaluated via density functional theory under MCM environment in comparison to various organic solvents.

The second part of the research, using density functional theory, we have focused on the design of novel heterogeneous catalyst that promotes electrochemical CO2 reduction to formic acid. Such highly active and stable electrocatalysts can be obtained by modifying chemical and physical properties of metal surfaces via a deposition of transition metal monolayer on graphene. The hybridization of sp and d orbitals between graphene and metal, which significantly reduces the local density of states of d-band of metals and increased s-and p-orbital of graphene near the Fermi level, leads to a strong covalent bonding between late transition metal monolayer and graphene (M/G). In addition, we discovered that the charge polarization on graphene in M/G induces a deposition of another thin metallic film on the graphene, thus forming M/G/M structures. Finally, the overpotential required for CO2 reduction to formic acid has been calculated on M/G and M/G/M structures to assess true catalytic activity as well as hydrogen evolution reaction and CO2 reduction to carbon monoxide for the selectivity evaluation.

Committee

• Prof. Christopher W. Jones – School of Chemical and Biomolecular Engineering
• Prof. Natalie Stingelin– School of Materials Science and Engineering
• Prof. Faisal M. Alamgir – School of Materials Science and Engineering
• Prof. Marcus Weck – Department of Chemistry, New York University