CHE 598 Seminar: “Correlating structure and function for nanoparticle catalysts”

About the event

Presenter, Dr. Graeme Henkelman, Professor from the University of Texas at Austin

Graeme Henkelman is a professor of chemistry at the University of Texas at Austin.  He did his undergraduate work in physics at Queen’s University in Canada, a PhD in chemistry at the University of Washington, and a postdoc at Los Alamos National Lab before starting at UT over ten years ago.  His research group has focused on computational methods for modeling reaction dynamics over experimental time scales.  These methods are applied to the challenge of developing new materials for energy applications including catalysts and batteries.

Correlating Structure and Function for Nanoparticle Catalysts

Metal nanoparticles of only 100-200 atoms are synthesized using a dendrimer encapsulation technique to facilitate a direct comparison with density functional theory (DFT) calculations in terms of both structure and catalytic function.  Structural characterization is done using electron microscopy, x-ray scattering, and electrochemical methods. Combining these tools with DFT calculations is found to improve the quality of the structural models. DFT is also successfully used to predict trends between structure and composition of the nanoparticles and their catalytic function for reactions including the reduction of oxygen and selective hydrogenation. This investigation demonstrates some remarkable properties of the nanoparticles, including facile structural rearrangements and nanoscale tuning parameters which can be used to optimize catalytic rates. In this presentation I will focus on a pair of random alloy bimetallic nanoparticles which have complete different trends in hydrogenation activity as a function of composition. Pd/Au is found to be tunable as a function of composition whereas Pt/Au is not. The reason behind these different behaviors will be discussed.