24th Annual Stauffer Lectureship (Day 1 of 2): Professor Sharon Hammes-Schiffer, Yale University

24th Annual Stauffer Lectureship (Day 1 of 2): Professor Sharon Hammes-Schiffer, Yale University (Host: Lynette Cegelski and Tom Markland)

About the Seminar

"Proton-Coupled Electron Transfer in Catalysis and Energy Conversion"

Proton-coupled electron transfer (PCET) reactions play a vital role in a wide range of chemical and biological processes. In these reactions, an electron and a proton move in a coupled manner, often between different donors and acceptors, and could move in the same or different directions. Moreover, PCET reactions may be sequential or concerted and could involve multiple electrons and protons. A general theory has been developed to describe all of these types of PCET reactions and has been applied to PCET in solution, proteins, nanoparticles, and electrochemical systems. This general PCET theory includes the quantum mechanical effects of the active electrons and transferring proton(s), as well as the motions of the proton donor-acceptor mode and solvent or protein environment. This theory has assisted in the interpretation of experimental data and has provided experimentally testable predictions.

This talk will summarize the key elements of this PCET theory and will present a variety of applications to catalysis and energy conversion. Applications to PCET in enzymes, molecular electrocatalysts for hydrogen production and water splitting, artificial photosynthesis, metal-oxide nanocrystals, proton discharge on a metal electrode, and photoreceptor proteins will be discussed. These studies have identified the thermodynamically and kinetically favorable mechanisms, as well as the roles of proton relays, excited vibronic states, hydrogen tunneling, reorganization, and conformational motions. The resulting insights are guiding the design of more effective catalysts and energy conversion devices.

About the Speaker

Sharon Hammes-Schiffer received her B.A. in Chemistry from Princeton University in 1988 and her Ph.D. in Chemistry from Stanford University in 1993, followed by two years at AT&T Bell Laboratories.  She was the Clare Boothe Luce Assistant Professor at the University of Notre Dame from 1995-2000 and then became the Eberly Professor of Biotechnology at The Pennsylvania State University until 2012, when she became the Swanlund Professor of Chemistry at the University of Illinois Urbana-Champaign.  Since 2018, she has been the John Gamble Kirkwood Professor of Chemistry at Yale University.  She is a Fellow of the American Physical Society, American Chemical Society, American Association for the Advancement of Science, and Biophysical Society.  She is a member of the American Academy of Arts and Sciences, the U.S. National Academy of Sciences, the International Academy of Quantum Molecular Science, and the Basic Energy Sciences Advisory Committee.  She was the Deputy Editor of The Journal of Physical Chemistry B and is currently the Editor-in-Chief of Chemical Reviews.  She is on the Board of Reviewing Editors for Science and has served as Chair of the Physical Division and the Theoretical Subdivision of the American Chemical Society. She has over 250 publications, is co-author of a textbook entitled Physical Chemistry for the Biological Sciences, and has given more than 380 invited lectures.