This year's Kaufman Memorial Lecture speaker is Prof. Franz M. Geiger, Northwestern University.

Talk Title: They flip before they split! From Stern to Helmholtz to Modern Molecular Electrochemistry

Abstract: Electrochemical water splitting begins in the nanoscopic layer of water molecules that sits directly on an electrode surface. In two recent studies, we developed a nonlinear optical method that reveals, for the first time, how many of these “Stern layer” water molecules must flip their orientation—and how much work that flipping requires—before the oxygen evolution reaction (OER) can proceed. On hematite photoanodes, we find that one to two monolayers of water reorient at high pH, and that the energy needed to flip them matches the cohesive energy of liquid water, which helps explain hematite’s large overpotential, perhaps causally.  On nickel electrodes, we observe a similar transition: a full monolayer aligns its oxygen atoms toward the surface before any Faradaic current flows, requiring ~80 kJ/mol of work.  These results identify water flipping as a measurable, energetically significant step in electrocatalysis and point to new strategies for lowering OER overpotentials by engineering the interfacial water structure. Additional examples with Fe-doped nickel and Ti-doped hematite are presented as well, where the latter shows significantly more favorable water flipping upon photo excitation. Real-time tracking of water flipping during rapid alternating polarity is demonstrated as well to show evidence for ratcheting. 

J. Am. Chem. Soc., 147, 14308-15 (2025), J. Am. Chem. Soc., 147, 33273-80 (2025), J. Am. Chem. Soc., 147, 40338-46 (2025), Science Advances, 11, ado8536 (2025), Nature Communications, 16. 3585 (2025), Nature Communications, 15 (1), 5326 (2024), ACS Catalysis, in press (2025)

Speaker Bio: Franz Geiger is currently the Charles E. and Emma H. Morrison Professor of Chemistry at Northwestern University, where he leads major research collaborations that involve experiments and computations to study the special role that surfaces and interfaces play in the world. He is a Fellow of the Alfred P. Sloan Foundation, the American Association for the Advancement of Science (AAAS), and the Royal Society of Chemistry (RSC). He is the recipient of the 2021 ACS Nobel laureate Signature Award (as preceptor, with Paul Ohno as student), the 2017 Friedrich Wilhelm Bessel Prize of the Alexander von Humboldt (AvH) Foundation, and the 2016 Faculty Diversity Award from Northwestern University’s Graduate School. He served as Senior Editor and was appointed to Executive Editor at the Journal of Physical Chemistry of the American Chemical Society (ACS), as chair of the Experimental Physical Chemistry (EXP) subdivision of the ACS Physical Chemistry Division, on the Science Board of the Telluride Science Research Center (TSRC), on the International Advisory Board of the Pacific Conference on Spectroscopy and Dynamics, (PCSD), and on the Chemical Sciences Roundtable of the National Academy of Sciences (NAS). He was the Ralph Grim Mineralogy Lecturer at the University of Illinois, the “Interdisciplinary Problems in Chemistry and Physics” Lecturer at the University of Maryland, a Baker Lecturer at Cornell University, and the 2025 Kaufman Lecturer at the University of Pittsburgh. Geiger joined the chemistry faculty of Northwestern University in 2001. He is a native of Berlin, Germany, where he received his Vordiplom in chemistry at the Technische Universitaet in 1993. He earned his PhD in 1998 at Georgetown University working with Janice Hicks as a NASA Fellow in Earth Systems Science, and was a NOAA Postdoctoral Fellow in Climate and Global Change with Mario Molina at MIT.

See more of Dr. Geiger's research on his lab website: https://geiger-lab.northwestern.edu/