title: The porosity, acidity, and reactivity of dealuminated zeolite ZSM-5 at the single particle level: the influence of the zeolite architecture.
abstract: A combination of atomic force microscopy (AFM), high-resolution scanning electron microscopy (HR-SEM), focused-ion-beam scanning electron microscopy (FIB-SEM), X-ray photoelectron spectroscopy (XPS), confocal fluorescence microscopy (CFM), and UV/Vis and synchrotron-based IR microspectroscopy was used to investigate the dealumination processes of zeolite ZSM-5 at the individual crystal level. It was shown that steaming has a significant impact on the porosity, acidity, and reactivity of the zeolite materials. The catalytic performance, tested by the styrene oligomerization and methanol-to-olefin reactions, led to the conclusion that mild steaming conditions resulted in greatly enhanced acidity and reactivity of dealuminated zeolite ZSM-5. Interestingly, only residual surface mesoporosity was generated in the mildly steamed ZSM-5 zeolite, leading to rapid crystal coloration and coking upon catalytic testing and indicating an enhanced deactivation of the zeolites. In contrast, harsh steaming conditions generated 5-50 nm mesopores, extensively improving the accessibility of the zeolites. However, severe dealumination decreased the strength of the Brønsted acid sites, causing a depletion of the overall acidity, which resulted in a major drop in catalytic activity.
authors: Inorganic Chemistry and Catalysis, Debye Institute for NanoMaterials Science, Utrecht University, Universiteitsweg 99, 3584 CG Utrecht, The Netherlands.
authors: Luis R
authors: LR
authors: Aramburo
authors: Lukasz
authors: L
authors: Karwacki
authors: Pablo
authors: P
authors: Cubillas
authors: Shunsuke
authors: S
authors: Asahina
authors: D A Matthijs
authors: DA
authors: de Winter
authors: Martyn R
authors: MR
authors: Drury
authors: Inge L C
authors: IL
authors: Buurmans
authors: Eli
authors: E
authors: Stavitski
authors: Davide
authors: D
authors: Mores
authors: Marco
authors: M
authors: Daturi
authors: Philippe
authors: P
authors: Bazin
authors: Paul
authors: P
authors: Dumas
authors: Fréderic
authors: F
authors: Thibault-Starzyk
authors: Jan A
authors: JA
authors: Post
authors: Michael W
authors: MW
authors: Anderson
authors: Osamu
authors: O
authors: Terasaki
authors: Bert M
authors: BM
authors: Weckhuysen
mesh_terms: D006863:Hydrogen-Ion Concentration; D018613:Microscopy, Confocal; D008855:Microscopy, Electron, Scanning; D056951:Photoelectron Spectroscopy; D016062:Porosity; D013055:Spectrophotometry, Infrared; D017641:Zeolites / Q000737:chemistry*
chemical_list: C570564:ZSM-5 zeolite; D017641:Zeolites