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MSE Seminar: “In Situ Probe of Structure and Dynamics at Metal electrode/Electrolyte Interface: Interfacial Structure, Electro-induction Effect, and Hot Electron Transfer”
March 5 at 10:30 AM - 12:00 PM
Structure and dynamics of electric double layer (EDL), the sub-nanometer region at the electrode/electrolyte interface, are essential to the function and performance of many energy conversion and storage devices, ranging from electrolyzers, photoelectrochemical cells, fuel cells to batteries. In situ probe of the EDL structure and dynamics at the molecular level requires advanced molecular spectroscopic tools with interfacial sensitivity and/or selectivity. In this talk, I will discuss three recent studies in developing and applying vibrational sum frequency generation (VSFG) spectroscopy and surface enhanced Raman spectroscopy (SERS) as powerful in situ interface specific/sensitive vibrational spectroscopic tools. 1) Using combined VSFG and DFT calculation, we determine the binding structure of a molecular CO2 reduction catalyst on metal electrodes and interfacial electric field profile in the EDL, revealing surprisingly large electrode induction effects on molecular catalyst. 2) Using combined SERS and MD simulation, we obtain an atomistic view of the structure of solvent and ion molecules at the EDL, revealing an unconventional interfacial water structure change at high negative electrode polarizations in water-in-salt electrolytes. 3) Using time-resolved VSFG and SERS, we directly measure hot electron transfer induced selective adsorbate mode excitation on metal nanoparticles and electrodes, suggesting the possibility of plasmon (or light)-enhanced electrochemistry.
Tianquan (Tim) Lian
John H. and Margaret B. Fassitt Professor of Chemistry, Vagelos Institute of Energy Science and Technology, University of Pennsylvania
Tianquan (Tim) Lian received BS degree from Xiamen University in China in 1985, MS degree from Fujian Institute of Research on the Structure of Matter (with Prof. Hongyuan Shen) in 1988 and PhD degree from University of Pennsylvania (with Prof. Robin Hochstrasser) in 1993. After postdoctoral training in the University of California at Berkeley (with Prof. Charles B. Harris), he joined the faculty of chemistry department at Emory University in 1996, where he was promoted to Associate Professor in 2002, Full Professor in 2005 and William Henry Emerson Professor of Chemistry in 2008. In August 2025, Tim Lian joined the Department of Chemistry and Vagelos Institute of Energy Science and Technology of the University of Pennsylvania as the John H. and Margaret B. Fassitt Professor of Chemistry. Tim Lian serves as the Editor-in-Chief of the Journal of Chemical Physics since Jan. 1, 2019 and has been the recipient of a few notable recognitions, including NSF CAREER award, Alfred P. Sloan fellowship, Kavli Frontier of Science fellow, APS fellow, ACS PChem Division Award for Senior Experimental Physical Chemistry, and AAAS Fellow. Tim Lian’s research interest is focused on developing and applying advanced in situ ultrafast and nonlinear spectroscopy tools to enable direct probe of interfacial structure, dynamics, and reaction mechanisms in nanomaterials and on electrodes and photoelectrodes and to advance the understanding of fundamental problems in energy conversion.