Episode 5: Theoretical framework predicts real-world industrial catalytic conditions

MRS Bulletin Materials News Podcast

In this podcast episode, MRS Bulletin’s Elizabeth Wilson interviews Manos Mavrikakis from the University of Wisconsin–Madison about his group’s theoretical work on real-world industrial catalytic conditions. It is often assumed that most catalyst surface atoms stay in place during a reaction, firmly bonded to their metal neighbors. However, Mavrikakis’s theoretical framework shows that under industrial reaction conditions, a surprising amount of metal–metal bond breaking is likely happening during catalytic reactions. This framework predicts that under reaction conditions, some adsorbed molecules have the strength to scavenge metal atoms from the catalyst particle, causing metal atoms to be ejected to a different spot on the metal surface. Bonds between metal atoms in certain geometries such as kinks can also break, even without adsorbed species, due to heat. However, the presence of reaction molecules may greatly increase the frequency of these events. The ejected metal atoms can then move around on the surface, collect together into groups such as trimers, tetramers, hexamers, or larger ensembles, forming entirely new types of active sites. This work was published in Science.