Van Marum Colloquium: Unraveling Catalytic Reactions at the Solid-Gas and Solid-Liquid Interface – Active Sites and their Surroundings
- Date
- Friday 14 June 2024
- Time
- Location
-
Gorlaeus Building
Einsteinweg 55
2333 CC Leiden - Room
- CM.3.23
Abstract
Surface processes occurring at complex material interfaces are crucial for various applications, particularly in heterogeneous catalysis. Defining “the active site” is often cited as the proverbial Holy Grail in catalysis research as by understanding it, one may manipulate reactions at will. In realistic systems operating at relevant conditions of temperature, pressure and with often high degrees of material complexity, however, is not trivial to define “an active site” in the traditional sense. We are particularly interested in understanding in such realistic systems 1) the contribution of the dynamic nature of processes at the interface on reaction kinetics, 2) the interplay of near-surface energetics on catalyst properties and reaction kinetics (i.e., confinement or solvation).
I will briefly introduce the multimodal approach we apply and further develop that combines homodyne detection with operando spectroscopy. Through the application of a temporal stimulus of interest with time-variant system analysis approaches, we can solve for, and group, desired system features of interest, including time, disorder, and non-correlated noise. This approach will then be demonstrated to elucidate the role of surface dynamics in “structure insensitive” ethene hydrogenation over Ni-based heterogeneous thermocatalysts using high-time resolution X-ray absorption spectroscopy (XAS). In the remaining part of the talk, the extension of this method to electrocatalysis will be discussed, focusing on studying the electric double layer in aqueous phase CO2 electroreduction over polycrystalline Cu, as well as the effect of electrolyte properties on Pt nanoparticles during the ammonia oxidation reaction and hydrogen evolution reaction.