Presented by Qingying Jia,
Dept. of Chemistry and Chemical Biology, Northeastern University, Boston, MA
The development of novel electrode materials is hindered by the lack of fundamental understanding of the precise structural effects on the catalytic activity and reaction mechanism. In this regard, the synchrotron based spectroscopic technique of x-ray absorption spectroscopy (XAS) offers unique insights into electrode processes by providing simultaneous electronic and structural information of the electrode materials under actual in situ cell operating conditions. In this talk, we will present our work of using in situ XAS in combination with ab initio multiple-scattering calculations to reveal the structural and electronic properties of various catalysts including Pt-based and non-Pt cathode catalysts for proton exchange membrane fuel cells (PEMFCs), as well as catalysts for lithium batteries. The established structure-property correlations of these materials provide further insights into the origin of the enhanced catalytic activity and stability of Pt-based alloys, the nature of the active sites of N-functionalized graphene-based materials, and the roles of cobalt phthalocyanine in delivering the full four-electron reduction of O2 to Li2O in lithium-air batteries. These work together show that to truly achieve the rational design of catalysts it is critical to identify the atomic arrangement of catalysts under condition relevant to catalytic reactions.
