title: High-resolution single-molecule fluorescence imaging of zeolite aggregates within real-life fluid catalytic cracking particles.
abstract: Fluid catalytic cracking (FCC) is a major process in oil refineries to produce gasoline and base chemicals from crude oil fractions. The spatial distribution and acidity of zeolite aggregates embedded within the 50-150 μm-sized FCC spheres heavily influence their catalytic performance. Single-molecule fluorescence-based imaging methods, namely nanometer accuracy by stochastic chemical reactions (NASCA) and super-resolution optical fluctuation imaging (SOFI) were used to study the catalytic activity of sub-micrometer zeolite ZSM-5 domains within real-life FCC catalyst particles. The formation of fluorescent product molecules taking place at Brønsted acid sites was monitored with single turnover sensitivity and high spatiotemporal resolution, providing detailed insight in dispersion and catalytic activity of zeolite ZSM-5 aggregates. The results point towards substantial differences in turnover frequencies between the zeolite aggregates, revealing significant intraparticle heterogeneities in Brønsted reactivity.
authors.affiliation: Debye Institute for Nanomaterials Science, Faculty of Science, Utrecht University, Universiteitsweg 99, 3584 CG, Utrecht (The Netherlands).
authors.forename: Zoran
authors.initials: Z
authors.lastname: Ristanović
authors.forename: Marleen M
authors.initials: MM
authors.lastname: Kerssens
authors.forename: Alexey V
authors.initials: AV
authors.lastname: Kubarev
authors.forename: Frank C
authors.initials: FC
authors.lastname: Hendriks
authors.forename: Peter
authors.initials: P
authors.lastname: Dedecker
authors.forename: Johan
authors.initials: J
authors.lastname: Hofkens
authors.forename: Maarten B J
authors.initials: MB
authors.lastname: Roeffaers
authors.forename: Bert M
authors.initials: BM
authors.lastname: Weckhuysen
mesh_terms: D002384:Catalysis; D008856:Microscopy, Fluorescence / Q000379:methods*; D017641:Zeolites / Q000737:chemistry*
chemical_list: D017641:Zeolites
keywords: Brønsted acidity; fluid catalytic cracking; fluorescence; single-molecule microscopy; zeolites