Proton-coupled electron transfer (PCET) reactions play a vital role in a wide range of chemical and biological processes. This talk will describe the theory of PCET and applications to catalysis and energy conversion. The quantum mechanical effects of the active electrons and transferring protons, as well as the motions of the donor-acceptor modes and solvent or protein environment, are included in a general theoretical formulation. This formulation enables the calculation of rate constants and kinetic isotope effects for comparison to experiment and the study of nonequilibrium dynamics. Applications to PCET in enzymes, molecular electrocatalysts, proton wires, nanocrystals, proton discharge on electrodes, 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, electrostatics, and conformational motions. The resulting insights are guiding the design of more effective catalysts and energy conversion devices.
Sharon Hammes-Schiffer received her B.A. from Princeton and her Ph.D. from Stanford, followed by two years at AT&T Bell Labs. Her academic career progressed from the University of Notre Dame to Pennsylvania State University to University of Illinois, and she is currently the John Gamble Kirkwood Professor 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, and the International Academy of Quantum Molecular Science. She has received the ACS Award in Theoretical Chemistry, the Royal Society Bourke Award, and the Hirschfelder Prize in Theoretical Chemistry. She is currently the Editor-in-Chief of Chemical Reviews and is on the Board of Reviewing Editors for Science.