NANODYNAMICS · Hidden in the Noise: Transient Details of Nanoparticle-Catalyzed Reactions Under Challenging Conditions

Metal nanoparticle-based catalysts drive our chemical industry and will be an essential tool to shift away from fossil-resources. Despite their exigence, new catalysts are often still found by trial and error rather than designed rationally. Although recent fundamental studies from our own research and others yield important new insights, there is a lack of methodology to investigate the subtle transient details missing in our understanding at the very high pressures that are often industrially relevant. Details such as reaction mechanisms, or dynamic surface equilibria at more than 100 bar are evidently greatly relevant to rationally designing better catalysts, yet have so far been outside of the realm of experimental characterization which hampers progress. Our key objective is to generate fundamental understanding of supported metal nanoparticle catalyst dynamics at work under relevant high-pressure conditions (up to 100 bar), with a strong focus on studying the Haber-Bosch reaction. To achieve this, we will utilize three recent developments: We will (1) employ specially designed reactors where laminar flow standing wave stimulation will be used, (2) perform high-time resolution resonant-Surface-enhanced infrared spectromicroscopy, and spatially resolved quick-X-ray absorption spectroscopy and (3) use our noise classification algorithm and further statistical data mining for quantification of surface site participation, and dynamics. In this way we will be able to differentiate important but miniscule reaction details from noise. These novel methods will be combined to gain insight into dynamic active sites, and equilibria that may exist at high pressure. The new insights will shift our fundamental knowledge from ‘static approximation’ to ‘dynamic reality’ and will offer direction in a new path of activity design improvements, dynamic site tailoring.