Insights into electrochemical reactions by in-situ techniques

ChEMS Seminar

Dr. Mary W. Louie

Postdoctoral Fellow

Department of Chemical and Biomolecular Engineering, UC Berkeley

Joint Center for Artificial Photosynthesis, Lawrence Berkeley National Laboratory

Electrochemical energy conversion devices have the potential to be the most efficient and clean solution to the world’s energy challenges. However, the performance of many such devices, for example, fuel cells, batteries and photoelectrochemical cells, is often limited by sluggish reactions at the electrodes. As such, a fundamental understanding of electrochemical reactions is critical for both optimal electrode design and proper catalyst selection.

Despite decades under pursuit, the pathways of many electrochemical reactions remain elusive. Electrochemical reactions are particularly complex because many species, such as electrons, ions and molecules, interact across multiple interfaces formed by the catalyst, electrolyte and gas phases. Electrical characterization, for example, by current-voltage or impedance measurements, can provide insight into such complex systems; however, interpretation of electrical data is often non-unique.

In this talk, I will present two examples of how in-situ techniques can clarify electrochemical processes occurring at electrode-electrolyte interfaces. In the first example, a

nanoscale electrode is employed to explore the spatial heterogeneity of oxygen reduction kinetics at the electrode-solid electrolyte interface. In the second example, I will show the power of confocal Raman microscopy for revealing the state of an electrocatalyst during operation; specifically I will discuss current studies on transition metal oxides for the catalysis of the oxygen evolution reaction in alkaline electrolytes.

BIO:

Dr. Mary Louie is a postdoctoral fellow at UC Berkeley and works at the Joint Center for Artificial

Photosynthesis. Her research interests center around understanding electrochemical reactions and

ion transport, with the goal of rationally designing catalysts and interfaces. She received her

Ph.D. in Chemical Engineering from Caltech in 2011 and her B.S. from the Chemical

Engineering and Materials Science and Engineering Program at UC Berkeley in 2005. Among

the awards Dr. Louie has received are the NSF Graduate Research Fellowship (2005), the Ludo

Frevel Crystallography Scholarship (2008), and the UC Presidential Postdoctoral Fellowship

(2011).