Description:

Dynamic Catalyst Materials and Reaction Environments for Oxygen Electrocatalytic Processes

Abstract: 

As our global energy supply expands to meet growing demands and evolves to incorporate a larger fraction of renewable sources, we must adapt our fuel and chemical production industry to effectively utilize, convert, or store these vital resources. Electrochemical catalysts enable a wide array of reactions that can operate at room temperature and pressure and provide a promising approach for buffering and storage of intermittent renewable energy sources. However, exciting opportunities for electrochemical technologies are limited by our understanding of dynamic catalyst materials that drive these reactions, as well as the complex interplay between bulk reactor properties and the local catalyst environment influencing reaction efficiency and selectivity. Research in the Seitz lab aims to address both challenges, and this talk will present examples of recent work in these areas.

The oxygen evolution reaction (OER) is a critical electrocatalytic process that uses water as an abundant resource to provide the necessary protons and electrons to drive myriad fuel-producing electroreductive reactions. While there are very few OER catalysts that are both active and stable in acidic conditions, development of such catalysts would have a direct impact on polymer electrolyte membrane-based water electrolyzers for sustainable fuel production. We present a series of iridate perovskite catalysts that significantly outperform rutile IrO2, a longtime benchmark catalyst for OER in acidic conditions. Accelerated stability testing of catalytic activity is complemented by a variety of materials characterization techniques to elucidate properties that lead to enhanced activity and possible degradation mechanisms.

In comparison, the oxygen reduction reaction (ORR) is a critical process for fuel cell operation, but can also be used for production of hydrogen peroxide, an environmentally friendly oxidant used in various chemical industries and for environmental remediation. On-site electrocatalytic production of H2O2 is attractive for its potential to mitigate high costs and safety concerns with transporting concentrated solutions of highly reactive H2O2. We present insights to catalyst performance and ORR mechanisms that are affected by systematically tuned bulk and local reaction environment, with emphasis on mass transport and electrolyte composition (pH, charge carrier density).

Bio:

Linsey Seitz joined the faculty of the Chemical and Biological Engineering Department at Northwestern University in Fall 2018. She received her B.S. (2010) in Chemical Engineering from Michigan State University supported with a full ride from the Alumni Distinguished Scholarship. Linsey received her M.S. (2013) and Ph.D. (2015) in Chemical Engineering from Stanford University, followed by postdoctoral studies at the Karlsruhe Institute for Technology in Germany. Linsey has been named an NSF Graduate Research Fellow, a Stanford DARE Fellow, a Helmholtz Postdoctoral Fellow, and a two-time Scialog Fellow. Her research at the interface of catalysis and spectroscopy has taken her to a number of synchrotron facilities to conduct in situ studies, including the Stanford Synchrotron Radiation Lightsource in Menlo Park, CA, the Advanced Light Source in Berkeley, CA, the KARA Synchrotron Radiation Source in Karlsruhe, Germany, and the Advanced Photon Source in Lemont, IL.