Mimicking industrial aging in fluid catalytic cracking: A correlative microscopy approach to unravel inter-particle heterogeneities

• Published in: Journal of catalysis Vol. 404; pp. 634 - 646
• Main Authors: Gambino, M., Nieuwelink, A.E., Reints, F., Veselý, M., Filez, M., Ferreira Sanchez, D., Grolimund, D., Nesterenko, N., Minoux, D., Meirer, F., Weckhuysen, B.M.
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 01.12.2021
• Subjects: Artificial deactivation; Catalyst deactivation; Fluid catalytic cracking; Microscopy; Fluid catalytic cracking; Microscopy; Artificial deactivation; Catalyst deactivation
• ISSN: 0021-9517; 1090-2694
• DOI: 10.1016/j.jcat.2021.10.012

[Display omitted] •A correlative X-ray fluorescence and confocal fluorescence microscopy approach is used to track metals, acidity and accessibility in Fluid Catalytic Cracking (FCC) materials.•The developed tool allows to assess the effectiveness of artificial deactivation protocols to mimic real-life deactivation occurring in the riser-regeneration FCC reactor.•The developed protocol allows to discriminate between FCC catalyst particles and additives, containing zeolite ZSM-5 material. Artificially mimicking aging of an equilibrium catalyst (ECAT) is an effective strategy to model the deactivation of a Fluid Catalytic Cracking (FCC) catalyst during refinery operations. Herein, we have used a correlative microscopy approach to unravel inter-particle spatial heterogeneities in artificially deactivated catalysts (DCATs) and compared them with a real-life ECAT containing on average 3800 ppm of Ni and 2300 ppm of V, and a set of density separated ECAT fractions. By doing so we could rationalize the effect of metal contaminants on catalyst acidity and pore accessibility. More specifically, the Fe, Ni, and V distributions were obtained using X-Ray Fluorescence (XRF), while Confocal Fluorescence Microscopy (CFM) after thiophene and Nile Blue A staining, respectively provided a visualization of Brønsted acid sites and accessibility distribution. We found that not only the metal poisons distribution, but also hydrothermal degradation, that affects ECATs dealumination and related acidity drop, need to be properly reproduced by artificial catalyst deactivation protocols. Fe contamination must also be taken into account since it affects matrix accessibility.