Experimental and theoretical evidence for promotional effect of acid sites on the diffusion of alkenes through small-pore zeolites

michel — Mon, 01 Feb 2021 11:12:41 +0000

P. Cnudde, E. A. Redekop, W. Dai, N.G. Porcaro, M. Waroquier, S. Bordiga, M. Hunger, L. Li, U. Olsbye, V. Van Speybroeck

Angewandte Chemie int. Ed.

60(18): 10016-10022

2021

Abstract

The diffusion of saturated and unsaturated hydrocarbons is of fundamental importance for many zeolite‐catalyzed processes. Transport of small alkenes in the confined pores of narrow pore zeolites can become hindered, resulting in a significant impact on the ultimate product selectivity and separation. Herein, intracrystalline light olefin/paraffin diffusion through the 8‐ring windows of zeolite SAPO‐34 is characterized by a complementary set of first‐principle molecular dynamics simulations, PFG‐NMR experiments and pulse‐response Temporal Analysis of Products measurements, yielding information at different length and time scales. Our results clearly show a promotional effect of the presence of Brønsted acid sites on the diffusion rate of ethene and propene, whereas transport of alkanes is found to be insensitive to the presence of acid sites. The enhanced diffusivity of unsaturated hydrocarbons is ascribed to the formation of favorable π‐H interactions with acid protons, as confirmed by IR spectroscopy measurements. The acid site distribution is proven to be an important design parameter for optimizing product distributions and separations.

DOI

http://dx.doi.org/10.1002/anie.202017025

How Acidity Influences Light Olefin Diffusion in H-SAPO-34 Zeolites

cnudde — Fri, 15 Dec 2023 09:17:08 +0000

P. Cnudde, E. A. Redekop, M. Waroquier, W. Dai, U. Olsbye, V. Van Speybroeck

ISBN/ISSN:

Talk

Conference / event / venue

8th Conference of the Federation of European Zeolite Associations (FEZA 2021)

Online

Monday, 5 July, 2021 to Friday, 9 July, 2021

Diffusion in the MTO process: The specific role of acid sites on the transport of light olefins

cnudde — Mon, 01 Aug 2022 15:07:50 +0000

P. Cnudde, E. A. Redekop, W. Dai, U. Olsbye, V. Van Speybroeck

ISBN/ISSN:

Talk

Conference / event / venue

XXIIIrd Netherlands' Catalysis and Chemistry Conference (NCCC XXIII)

Noordwijkerhout, The Netherlands

Monday, 9 May, 2022 to Wednesday, 11 May, 2022

Center for Molecular Modeling - W. Dai

Experimental and theoretical evidence for promotional effect of acid sites on the diffusion of alkenes through small-pore zeolites

Abstract

DOI

How Acidity Influences Light Olefin Diffusion in H-SAPO-34 Zeolites

Conference / event / venue

Diffusion in the MTO process: The specific role of acid sites on the transport of light olefins

Conference / event / venue