Title : Using X ray absorption spectroscopy (XAS) to probe single atom catalysts in carbon nanotubes

Abstract:

ingle-atom catalysts (SACs) are the smallest entities for catalytic reactions with high atomic efficiency, activity, and selectivity. However, practical applications of SACs are limited by single atom loading of less than 2 wt.% or alternatively aggregation of the SACs to form larger particles, e.g. nanoparticles. In our research we have developed a class of SACs based strictly on atomically dispersed transition metals on nitrogen-doped carbon nanotubes and characterised these using a variety of complementary methods, including X-ray absorption spectroscopy (XAS) at the Australian Synchrotron in Melbourne. This material contains up to 20 wt.% SACs [Yi Cheng et al, Adv. Mater. 30 (2018) 1706287]. In our presentation we will focus on the characterization aspect of the material with particular emphasis on XAS; sample preparation, data collection, and interpretation.

Biography:

Dr. Bernt Johannessen studied at Auckland University in New Zealand and then at the Australian National University graduating in 2007 with a PhD. He then worked as a beamline scientist at the Australian National Beamline Facility at the time located at the Photon Factory in Tsukuba, Japan, for two years. Following this appointment, he joined the team at the X-ray Absorption Spectroscopy beamline at the Australian Synchrotron, ANSTO, where he is now a Senior Scientist in the team. He has co-authored more than 70 peer-reviewed research articles in international journals.