Speaker
Description
Catalysts evolve dynamically under operating conditions. From atomic-scale restructuring to severe coke formation, the dynamic evolution of the catalyst structure is closely linked to changes in catalytic performance. Operando X-ray absorption spectroscopy (XAS) is a well-suited technique to probe the dynamic structural changes under realistic reaction conditions and to correlate rich information gained on the geometric and electronic structure of catalysts to the observed catalytic properties. Synchrotron radiation (SR) facilities have been widely used for operando XAS experiments. However, access to beamtime at SR facilities is limited by a highly competitive application process, which means that not all groups are guaranteed to secure beamtimes to answer their scientific questions promptly. More importantly, such limited access hinders development of new experimental setups (involving e.g., multiple experimental techniques, and dedicated infrastructure for monitoring catalysts’ performance), and limits possibilities for catalyst screening, considering the risk of wasting precious beamtime without success. Simultaneously, long-term monitoring of catalyst (de-)activation processes is crucial for their practical applications, and for bridging the gap between the lab-based studies and industrial conditions. However, long-term XAS studies are hardly compatible with the conventional SR beamtime access models.
This calls for the development of new methodologies for operando XAS experiments in a more accessible lab-based setting. Thanks to the recent development in X-ray optics and detectors, commercial lab-based XAS spectrometers become now increasingly accessible. However, these devices still must be adapted for operando studies. In this contribution we discuss our recent progress in enabling lab-based operando XAS investigations, on the example of catalysts both for electrochemical and thermally driven processes.
