Date: Thursday, Nov 3rd
Presenter: Prof. Zhenxing Feng, OSU Chemical Engineering
For electrochemical systems the gas/solid and liquid/solid interfaces are critical parts where many important reactions take place, such as oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). The understanding of the atomic, chemical and electronic structures of these interfaces in operation will reveal the electrochemical mechanism, and help design efficient energy conversion and storage devices. In this talk, I will first discuss a design principle study on spinel materials to explore their pseudocapacitive as well as electrochemical catalytic performance for ORR and OER. By combining electrochemical tests and in situ X-ray absorption spectroscopy measurements, we have figured out the property descriptors of spinel ferrites, and successfully applied them to predict and test the electrochemical properties of other transition metal spinels. In the second part of this talk, I will discuss in situ studies of oxide thin films as solid oxide fuel cells (SOFCs) for the understanding of the nano-scale structure and chemistry by a combination of X-ray diffraction and ambient pressure XPS. Such studies are extended to sub-angstrom scale by using Coherent Bragg Rod Analysis (COBRA) to directly reveal the 3-dimentional atomic structure as well as layer-by-layer elemental distribution of La1-xSrxCoO3-x epitaxial and (La1-ySry)2CoO4±x/La1-xSrxCoO3-x heteostructured thin films for oxygen catalytic applications. Finally I will conclude how to wisely use advanced in situ methods to obtain critical information for fundamental research and application needs.
Zhenxing Feng graduated from Peking University in China with BS in Physics. He obtained MS in Physics from McGill University in Montreal, Canada, and Ph.D. in Materials Science and Engineering of Northwestern University, USA. After two years postdoc experience in Electrochemical Energy Lab of Mechanical Engineering in MIT from 2011 to 2013, he went to Argonne National Lab to work on advanced batteries in Joint Center for Energy Storage Research (JCESR). In 2016, he moved to Oregon State University as an Assistant Professor in School of Chemical, Biological, and Environmental Engineering.