Inorganic Seminar - Seung Jun Hwang
Aug
12
2025
Description
The Inorganic Seminar Series presents: Seung Jun Hwang
POSTECH
Host: Kurtis Carsch
Title: Rational Design of Molecular Catalysts: Beyond Traditional Approaches with Internal Electric Fields, Biomimetics, and Main-Group Elements
WEL 2.122
The development of alternative energy sources beyond fossil fuels hinges on our ability to activate small molecules (H2, O2, CH4, CO2) through challenging multi-electron, multi-proton transformations. These processes face formidable kinetic barriers, requiring innovative catalytic strategies capable of managing complex electron transfer events.
Inspired by metalloenzymes containing polynuclear transition metal assemblies, our group synthesized a range of dicopper complexes mimicking the active site of zeolite to systematically investigate the impact of secondary elements on the reactivity and stability of critical intermediates formed during multi-electron oxidation reactions. This seminar will also discuss a novel approach for developing catalysts with controlled internal electric fields to enhance selectivity in small molecule fixations and reactivity of catalysts. Strong electric fields can dramatically affect the relative energies of competing transition states and control the reactivity of synthetic catalysts. Complementing these transition metal-based approaches, we also investigated whether main-group elements could mediate multi-electron chemistry. Our work with distorted phosphorus complexes revealed that phosphorus-ligand redox cooperativity can effectively manage four-electron redox processes, with simultaneous two-electron transfers occurring at both the phosphorus center and the redox-active ligand scaffold. This strategy has enabled the activation of O2 and various NOx species under remarkably mild conditions, demonstrating that transition metals are not always necessary for complex multi-electron transformations.
This seminar will discuss how these three complementary strategies—biomimetic design, internal electric field control, and main-group ligand redox cooperativity—collectively advance our capabilities in developing efficient catalysts for sustainable energy applications.