CANCELLED - Seminar entitled "Exploring the impact of carbon structure in low-temperature hydrogen fuel cells by electron microscopy"
|Starts:||14:00 12 Mar 2020|
|Ends:||15:00 12 Mar 2020|
|What is it:||Seminar|
|Organiser:||Department of Materials|
|Speaker:||Professor David Cullen|
Graphitized carbons play a critical role in the electrodes of polymer electrolyte membrane fuel cells. As a support material, they influence the activity and stability of Pt nanoparticles,
while also impacting the dispersion of proton-conducting ionomer, the distribution of pore space, and electrical conductivity. In platinum group metal-free catalysts, the role of the
graphitized support becomes even more critical, with graphene-hosted FeNx moeties serving as the active site for the oxygen reduction reaction in this class of materials.
The presentation will begin with a short summary of activities at ORNL’s Center for Nanophase Materials Sciences, then focus on the scanning transmission electron microscopy
(STEM) methods which have been applied to the study of the various carbon structures used in fuel cells. The valuable structure-property insights gained from techniques such as
single atom electron energy loss spectroscopy, 4D STEM, in situ pyrolysis, and electron tomography will be discussed. A brief overview of the current status of the hydrogen
economy in the United States will also be provided, as will a perspective of the key challenges that remain for fuel cells and hydrogen production, storage, and delivery.
Dave Cullen is a Senior Staff Scientist in the Electron and Atom Probe Microscopy Group at Oak Ridge National Laboratory (ORNL). He earned his Ph.D. in Materials Science and
Engineering from Arizona State University and joined ORNL as an Alvin M. Weinberg Fellow. He is a prolific, impactful author with an extensive list of national and international
collaborations established through projects funded by EERE’s Fuel Cell Technologies Office and the Center for Nanophase Materials Sciences, which is a DOE Office of Science User Facility.
He also holds a joint faculty appointment with the Bredesen Center for Interdisciplinary Research and Graduate Education at the University of Tennessee, Knoxville.
He received the Presidential Early Career Award for Scientists and Engineers, the highest honor bestowed by the U.S. government on outstanding scientists and engineers beginning
their independent careers, in 2019 in recognition of his groundbreaking scientific accomplishments in correlating the atomic structure and chemistry of fuel cell materials with fuel cell
durability and performance using advanced, analytical aberration-corrected scanning transmission electron microscopy.
Professor David Cullen
Organisation: Center for Nanophase Materials Sciences (CNMS), Oak Ridge National Laboratory (ORNL), USA
Travel and Contact Information
3rd Floor Seminar Room
National Graphene Insitute