Title: In Situ Probe of Structure and Dynamics at Metal electrode/Electrolyte Interface
Bio:
Biographical sketch. 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 (under the supervision of Prof. Hongyuan Shen) in 1988 and PhD degree from University of Pennsylvania (under the supervision of late Prof. Robin Hochstrasser) in 1993. After postdoctoral training with the late Professor Prof. Charles B. Harris in the University of California at Berkeley, Tim Lian joined the faculty of chemistry department at Emory University in 1996, where he was promoted to Associate Professor in 2002, Full Professor in 2005, Winship Distinguished Research Professor in 2007, and William Henry Emerson Professor of Chemistry in 2008. Tim Lian is currently the Editor-in-Chief of the Journal of Chemical Physics (since Jan. 1, 2019). Tim Lian is the recipient of a few notable recognitions, including NSF CAREER award, Alfred P. Sloan fellowship, Kavli Frontier of Science fellow (since 2012), APS fellow (since 2015), ACS PChem Division Award for Senior Experimental Physical Chemistry (2022), and AAAS Fellow. Tim Lian’s research interest is focused on in situ probe of the interfacial structure, dynamics, and reaction mechanisms in nanomaterials and electrochemical and photoelectrochemical devices. The Lian group will move to the Department of Chemistry at University of Pennsylvania on Sept. 1, 2025.
Abstract:
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, we directly measure hot electron transfer induced vibrational dynamics of adsorbates on metal electrodes, suggesting the possibility of plasmon (or light)-enhanced electrochemistry.
Student Host: Yuzhe Zhang, Yiwen Wang, Zhe Liu