Title:Designing Hybrid Electrodes to Dictate Oxygen Reduction Product Selectivity

Speaker:Prof. Edmund C. M. Tse,The University of Hong Kong

Time：June 14, 2019,3：00 p.m

Venue: Lecture Room 324, AISMST (Building #2, KeJiYuan, North Campus)

Faculties and students are warmly welcome.

South China Advanced Institute for Soft Matter Science and Technology

School of Molecular Science and Engineering

June 5, 2019

Brief Biography：

Edmund Tse received his Bachelor of Science degree in Chemistry specialized in Materials Science from the University of Virginia while gaining his undergraduate research experience under the guidance of Professor Brent Gunnoe. With a Croucher Foundation Scholarship, Edmund completed his doctoral studies with the co-supervision of Professor Andrew Gewirth and Professor Thomas Rauchfuss at the University of Illinois at Urbana-Champaign. In his PhD work, Edmund developed lipid-modified electrodes to probe transmembrane proton and ion transports that are central to many biological processes.

As a Croucher Research Fellow, Edmund finished his postdoctoral research work at the California Institute of Technology with Professor Jacqueline Barton as the advisor. Edmund developed DNA-modified electrodes to understand how proteins containing redox cofactors find and repair DNA damage efficiently. Edmund is now an assistant professor of bioinorganic chemistry at the Department of Chemistry in the University of Hong Kong. His research group focuses on developing hybrid bilayer membrane electrodes as platforms to modulate the reaction pathways and product selectivity of catalytic processes that involve protons and electrons.

Abstract

Reactions involving protons and electrons are central to many catalytic processes and energy applications.  In this talk, I will describe my laboratory’s efforts in developing a nanoscale organic-inorganic hybrid electrochemical platform to modulate independently the proton and electron transfer rates for oxygen reduction reaction (ORR). ORR is the chemical reaction that critically limits the performance of fuel cells and related energy conversion technologies. Our nanoscale electrochemical platform features a hybrid bilayer membrane (HBM) comprising of a self-assembled monolayer (SAM), an azide-alkyne click moiety, an ORR electrocatalyst, a phospholipid layer, and a proton transfer agent [1]. Each of these five controls one aspect of ORR, and together they determine the overall catalytic performance. Utilizing this modular nanosystem, the electron transfer rate can be adjusted by changing the SAM length, and the proton transfer rate can be tuned by the proton transfer agent in the lipid layer. The click moiety further allows for efficient attachment of various electrocatalytic units with other functionalities.  By regulating the relative rates of proton and electron transfer using our hybrid electrode architecture, we achieve higher selectivity for the four-electron process to generate water as the desired product without compromising the activity of the electrocatalyst. New data will also be presented to facilitate cross-discipline discussions on simulations for rational materials design.  In summary, our hybrid electrode system will provide unique insights into the optimal thermodynamic and kinetic parameters not only for ORR catalysts, but also offer new opportunities to enhance the performance of other catalysts for fuel generation and energy storage.

[1] Rajendra Gautam, Yi Teng Lee, Gabriel L. Herman, Cynthia M. Moreno, Edmund C. M. Tse, Christopher J. Barile, Controlling Proton and Electron Transfer Rates Enhances the Activity of an Oxygen Reduction Electrocatalyst Angew. Chem. Int. Ed.2018, 57, 13480-13483.