Chemical Imaging of Hierarchical Porosity Formation within a Zeolite Crystal Visualized by Small-Angle X-Ray Scattering and In-Situ Fluorescence Microscopy.
Angew Chem Int Ed Engl
; 60(25): 13803-13806, 2021 Jun 14.
Article
em En
| MEDLINE
| ID: mdl-33725373
ABSTRACT
Introducing hierarchical porosity to zeolites is vital for providing molecular access to microporous domains. Yet, the dynamics of meso- and macropore formation has remained elusive and pore space ill-characterized by a lack of (in situ) microscopic tools sensitive to nanoporosity. Here, we probe hierarchical porosity formation within a zeolite ZSM-5 crystal in real-time by in situ fluorescence microscopy during desilication. In addition, we introduce small-angle X-ray scattering microscopy as novel characterization tool to map intracrystal meso- and macropore properties. It is shown that hierarchical porosity formation initiates at the crystal surface and propagates to the crystal core via a pore front with decreasing rate. Also, hierarchical porosity only establishes in specific (segments of) subunits which constitute ZSM-5. Such space-dependent meso- and macroporosity implies local discrepancies in diffusion, performance and deactivation behaviors even within a zeolite crystal.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Idioma:
En
Revista:
Angew Chem Int Ed Engl
Ano de publicação:
2021
Tipo de documento:
Article
País de afiliação:
Holanda