Spectral X-ray ptychography for the investigation of technical catalysts

International audienceCatalysts are ubiquitous materials that play a major role in many areas of economy and everyday life. The development and study of catalysts is important for progress in areas such as environment, energy, and fuels, with the main goal being to improve the performance and efficiency of catalysts, especially at the industrial scale. Therefore, a thorough analysis is crucial to understand the relation between structure and performance, the deactivation process and the reasons for the loss of efficiency over the lifetime. This analysis is challenging, because technical catalysts are complex multicomponent bodies, ranging from dozens of μm to several cm, consisting of active phases, supports and additives in shaped forms suitable for their application. One of the most important conversion processes in petroleum refineries is Fluid Catalytic Cracking (FCC) in which heavy hydrocarbon fractions of crude oil are converted into valuable products such as olefins and aromatics [1]. For this process, FCC particles of 50-100 µm diameter are used in an up-flow reactor, where they move up, whereas the feed flows downward. During the short contact time, catalyst and feed can react. During this reaction the catalyst is partially deactivated by coke formed during the cracking and a subsequent regeneration cycle is required [2]. Thus, the characterization of the microstructure at different length scales with a spatial resolution at the nanometer length scale and a large field of view is necessary, but also the investigation of the location and chemical state of the active metallic sites in the structure