Ethylene formation by dehydration of ethanol over medium pore zeolites

Kinga Gołąbek; Karolina A Tarach; Urszula Filek; Kinga Góra-Marek

doi:10.1016/j.saa.2017.11.049

Ethylene formation by dehydration of ethanol over medium pore zeolites

Spectrochim Acta A Mol Biomol Spectrosc. 2018 Mar 5:192:464-472. doi: 10.1016/j.saa.2017.11.049. Epub 2017 Nov 23.

Authors

Kinga Gołąbek¹, Karolina A Tarach¹, Urszula Filek², Kinga Góra-Marek³

Affiliations

¹ Faculty of Chemistry, Jagiellonian University in Kraków, 2 Gronostajowa St., 30-387 Kraków, Poland.
² Jerzy Haber Institute of Catalysis and Surface Chemistry PAS, Niezapominajek 8, Kraków, Poland.
³ Faculty of Chemistry, Jagiellonian University in Kraków, 2 Gronostajowa St., 30-387 Kraków, Poland. Electronic address: kinga.gora-marek@uj.edu.pl.

PMID: 29216600
DOI: 10.1016/j.saa.2017.11.049

Abstract

In this work, the role of pore arrangement of 10-ring zeolites ZSM-5, TNU-9 and IM-5 on their catalytic properties in ethanol transformation were investigated. Among all the studied catalysts, the zeolite IM-5, characterized by limited 3-dimensionality, presented the highest conversion of ethanol and the highest yields of diethyl ether (DEE) and ethylene. The least active and selective to ethylene and C₃₊ products was zeolite TNU-9 with the largest cavities formed on the intersection of 10-ring channels. The catalysts varied, however, in lifetime, and their deactivation followed the order: IM-5>TNU-9>ZSM-5. The processes taking place in the microporous zeolite environment were tracked by IR spectroscopy and analysed by the 2D correlation analysis (2D COS) allowing for an insight into the nature of chemisorbed adducts and transition products of the reaction. The cage dimension was found as a decisive factor influencing the tendency for coke deposition, herein identified as polymethylated benzenes, mainly 1,2,4-trimethyl-benzene.

Keywords: 2D COS analysis; Acidity; Dehydration; Ethanol; IM-5; IR spectroscopy; TNU-9; ZSM-5.