Center for Catalysis and Surface Science (CCSS) Student Seminar Series
Friday, April 17, 2026 | 12-1pm CT
Ryan Hall, 4003 | 2190 Campus Drive
Join the Center for Catalysis and Surface Science (CCSS) for the Student Seminar Series. Hear from graduate students and postdoctoral scholars during two presentations. This month's speakers are Jeongmin Cho from the Mirkin Group and Mark Kazour from the Seitz Group.
About the Presentations
Speaker: Jeongmin Cho
Title: "DNA-engineered Photonic Crystals of Optical-Scale Dielectric Colloids toward Visible Photonic Bandgaps"
Abstract:
DNA-mediated assembly of colloidal particles provides a powerful route to fabricate photonic materials with structural color, yet achieving long-range ordered crystals at optical length scales remains a fundamental challenge. In particular, dielectric nanoparticles such as silica are highly attractive for photonic applications due to their low optical loss, characterized by a near-zero extinction coefficient (k ≈ 0) in the visible range, which minimizes light absorption. However, their large size and high density hinder controlled crystallization due to sedimentation and kinetic trapping.
We present a DNA-mediated assembly approach to realize highly ordered superlattices of optical-scale dielectric nanoparticles (≥100 nm) with tunable periodicity in the visible regime. Silica nanoparticles are functionalized with dense DNA shells via epoxy–amine coupling, enabling programmable and reversible interparticle interactions. By carefully controlling DNA hybridization thermodynamics and slow cooling kinetics, we achieve crystalline assemblies with domain sizes exceeding the threshold required for observable photonic response.
We demonstrate that structural color emerges only when both sufficient crystal size and crystallinity are achieved, with more highly ordered domains exhibiting stronger and more spectrally selective reflection, while less ordered or disordered assemblies show diminished or absent photonic signatures. Experimental optical responses are consistent with simulations based on periodic lattice structures, confirming that DNA-mediated assembly enables precise control over optical-scale ordering.
This work establishes DNA-mediated assembly of low-loss dielectric colloids as a viable pathway toward tunable photonic materials and provides design principles linking nanoscale programmability to macroscopic optical functionality.
Speaker: Mark Kazour
Title: "A Systemic Process Investigation of Tandem Electro- and Thermocatalytic Continuous Reactors for Hydrogen Peroxide-Mediated Cyclohexene Epoxidation"
Abstract:
Electrocatalysis offers a sustainable and safe alternative to fossil fuel-based chemical production by converting carbon feedstocks into value-added chemicals using renewable electricity. One promising target is the production of epoxides. Epoxides are key chemical intermediates to produce epoxies, pharmaceuticals, and textiles, yet electrochemical approaches to their synthesis remain limited by poor selectivity and low activity. Direct electrooxidation, in which electrons transfer from the electrode directly to the organic substrate, suffers from high overpotential and numerous by-products.
As an alternative, indirect electrooxidation via redox mediators such as hydrogen peroxide can enhance selectivity and activity towards the desired epoxide product, while maintaining industrially relevant current densities. In this approach, the electrochemically generated mediator subsequently reacts thermocatalytically to form the epoxide. Integrating electrocatalytic and thermocatalytic processes offers an industrially relevant path to improve performance, while mitigating safety and environmental risks.
Herein, we present a hydrogen peroxide-mediated cyclohexene epoxidation system that integrates a dual-membrane electrode assembly (MEA) solid-electrolyte electrolyzer with a downstream thermocatalytic flow reactor. The indirect electrooxidation strategy first produces hydrogen peroxide, which oxidizes cyclohexene downstream in a biphasic, thermocatalytic reactor. We evaluate the resiliency of the MEA towards continuous recycle operation, evaluating the impact of temperature modification and Na2WO4 catalyst addition.
This work highlights the operational flexibility of tandem electro- and thermo-catalytic reactor designs, especially for future integration into existing industrial thermochemical processes. Insight from this work supports the development of indirect electrooxidation platforms for scalable and flexible industrial applications.
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The mission of the Center for Catalysis and Surface Science (CCSS) is to promote interdisciplinary research fundamental to the discovery, synthesis, and understanding of catalysts and catalytic reactions essential to modern society. As a part of the Paula M. Trienens Institute for Sustainability and Energy, CCSS applies fundamental advances in catalysis science towards applications in alternative fuels, abatement of harmful emissions, resource recovery concepts, new processing routes, and many other strategies towards making chemicals more sustainable.
Jim Puricelli
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