Monday, March 12, 20123:00 PM - 4:00 PMCNLS Conference Room (TA-3, Bldg 1690)|
Peng ChenCornell University
Nanoparticles are important catalysts. Understanding their structure-activity correlation is paramount for developing better catalysts, but hampered by their inherent inhomogeneity: individual nanoparticles differ from one to another, and for every nanoparticle, it can change from time to time, especially during catalysis. Furthermore, each nanoparticle presents on its surface various types of sites, which are often unequal in catalytic reactivity. To overcome these challenges, my group has been developing single-molecule fluorescence imaging methods to study the catalytic activity and dynamics of metal nanoparticles at the single-particle level, in situ, and with real-time single-turnover resolution and nanometer precision. I will present how we interrogate the catalytic activity, mechanism, heterogeneous reaction pathways, selectivity, and surface-restructuring-coupled temporal dynamics of individual Au nanoparticles. I will also present our latest work in imaging and resolving catalytic reactions on a single nanocatalyst at nanometer resolution, which maps the reactivity of different surface sites and uncovers diverse spatial reactivity patterns at the nanoscale. This spatial resolution of catalysis also enables us to probe communication of catalytic reactions at different locations on a single nanorod, in much relation to allosteric effects in enzymes.
Host: Doug Shepherd