Time：2015.10.29 (Thursday) 14:00 PM
Location: 2# meeting room, conference center of energy building
Lecturer：Vijay K. Ramani
Hyosung S. R. Cho Endowed Chair Professor
Department of Chemical and Biological Engineering,Illinois Institute of Technology, Chicago
Abstract：
Research and development efforts directed towards chemically stable anion exchange membranes (AEMs) for solid alkaline fuel cellshave increased substantially over the past 5 to 10 years. AEMs also find possible applications in other energy storage and conversion technologies (e.g. metal-air batteries, solid alkaline electrolyzers and redox flow batteries). Developing AEMs that have robust alkaline stability has been a challengefor the past 40 years. Because the fixed cation sites are dubbed the ‘weak link’ in the AEM, many researchers have worked to explore more stable cation chemistries. The fixed cation sites with different chemical moieties are known to degrade by many different mechanisms perpetrated by hydroxide ion attack (e.g. Hoffman elimination, direct nucleophilic attack, rearrangement reactions via ylide intermediates). The objective of our AEMresearch is to discover which chemical constituents in the fixed cation site and polymer backbone permit hydroxide ion attack and to use this knowledge to prepare high performing, alkaline stable AEMs that do not feature these groups.
Our research group has employed 1D and 2D NMR techniques to study the degraded structure of linear polymer based AEMs. The NMR of degraded polysulfone (PSF)-based AEMs has demonstrated that the fixed cation site aids in the hydrolysis of ether linkages in the polysulfone backbone when exposed to very alkaline solutions. Additionally, the NMR experiments have revealed the formation of degradation products produced by reactive ylide intermediates. These and other key results will be discussed in the presentation.
Additionally, we have advanced the development of pyrochlore-based electrocatalysts with very high activity for the oxygen evolution reaction in alkaline media, and have demonstrated outstanding performance and durability in a solid alkaline electrolyzer. A summary of our work from an applications viewpoint (i.e. use of AEMs in devices such as solid alkaline fuel cells and electrolyzers) will also be presented, along with a discussion of extant challenges that remain to be addressed.
Biography:
Vijay Ramani holds the Hyosung S. R. Cho Endowed Chair in Engineering and is a Professor of Chemical Engineering at Illinois Institute of Technology, Chicago. His research interests lie at the confluence of electrochemical engineering, materials science, and renewable energy technologies. Current research directions in his group include multi-functional electrolyte and electrocatalyst materials for polymer based electrochemical systems, analyzing the source and distribution of overpotential (losses) in electrochemical systems, mitigating component degradation in electrochemical devices, and in-situ diagnostics to probe electrochemical systems.
NSF, ONR, and DOE have funded his research, with mechanisms including an NSF CAREER award (2009) and an ONR Young Investigator Award (ONR-YIP; 2010). He is the recipient of the 3M Non-tenured Faculty Award (2010) and the Supramaniam Srinivasan Young Investigator Award from the Energy Technology Division of the Electrochemical Society (2012). He is a past Chair of the Industrial Electrochemistry and Electrochemical Engineering Division of the Electrochemical Society, and currently serves as President of Area 1E of AIChE. He holds an Extraordinary Professorship in Chemical Resource Beneficiation at North West University, South Africa and has held an Adjunct Professorship in Chemical Engineering at IIT-Madras. He is currently also a visiting Professor at Tsinghua University. He is the co-Editor of ECS Interface.
Vijay has a Ph.D. in from the University of Connecticut, Storrs, and a B.E. from Annamalai University, India, both in Chemical Engineering.
Contract: Hongmei Yu, DNL0301