CHE 598 Seminar: Supported Metal Nanoparticle Catalysts and Electrocatalysts: Predicting Their Thermodynamic Stability and Correlating That With Their Catalytic Performance
About the event
SPEAKER: Dr. Charles T. Campbell, Professor Emeritus and B. Seymour Rabinovitch Endowed Chair, Department of Chemistry, University of Washington
BIOGRAPHY:
Prof. Charles T. Campbell is Professor Emeritus of Chemistry at the University of Washington, where he is also Adjunct Professor of Chemical Engineering and of Physics, and the Rabinovitch Endowed Chair in Chemistry. He received his BS (1975) and PhD (1979, under JM White) degrees at the University of Texas at Austin in Chemical Engineering and Chemistry, then did postdoctoral research in Germany with Gerhard Ertl (2007 Nobel Prize Winner) and was a staff member at Los Alamos National Lab (1981-1986). He is the author of over 380 publications (h-index = 108) and two patents on surface chemistry, catalysis, physical chemistry and biosensing. He is an elected Fellow of the ACS, the AVS and the AAAS, Honorary Fellow of the Chinese Chemical Society, and Member of the Washington State Academy of Sciences. He is a Member of the Academy of Distinguished Chemical Engineers of the University of Texas at Austin. He received the Arthur W. Adamson Award of the ACS, the ACS Award for Colloid or Surface Chemistry, the ACS Gabor Somorjai Award for Creative Research in Catalysis, the ACS Catalysis Award for Exceptional Achievements, the Gerhard Ertl Lecture Award, the Robert Burwell Award/Lectureship of the North American Catalysis Society, the Medard W. Welch Award of the AVS, the Gauss Professorship of the Göttingen Academy of Sciences, the Ipatieff Lectureship of Northwestern University and an Alexander von Humboldt Research Award. He serves as Editor-in-Chief of Surface Science Reports and of Catalysis Reviews in Science and Engineering, and on the boards of EES Catalysis, Catalysis Letters, Surface Science and Topics in Catalysis. He previously served as Editor-in-Chief of Surface Science for over ten years.
ABSTRACT:
Many important catalysts and electrocatalysts for energy and environmental technologies involve late transition metal nanoparticles dispersed across the surface of some oxide or carbon support. The activity and long-term stability of these materials depend strongly on particle size below 7 nm, and, in this size range, upon the composition and atomic-level structure of the support surface. We show here that the chemical potential of the metal atoms in such supported catalysts provides a convenient descriptor of their performance as heterogeneous catalysts that captures many of the effects of particle size, metal-metal alloying and support on catalyst performance. Based on microcalorimetric measurements of metal adsorption energies, the metal chemical potential is shown to be predictable as a function of metal particle size and the adhesion energy (per unit area) at the metal / support interface. These measurements can be analyzed to provide this adhesion energy, which also determines the equilibrium particle shape and wetting propensity to the support material. For oxide supports, this adhesion energy correlates predictably with the metal element’s oxophilicity, as we defined based on heats of oxide formation from gaseous metal atoms plus O2. For carbon supports, this adhesion energy correlates predictably with the metal element’s carbophilicity, as we defined based on DFT estimates of C atom adsorption energies. These correlations provide predictions of metal chemical potential that can predict catalyst deactivation rates via sintering and can enable catalyst design.