Epoxidation of ethylene by anion radicals of [alpha]-oxygen on the surface of FeZSM-5 zeolite

• Published in: Journal of catalysis 2014-01, Vol.309, p.453
• Main Authors: Starokon, Eugeny V, Parfenov, Mikhail V, Pirutko, Larisa V, Soshnikov, Igor E, Panov, Gennady I
• Format: Article
• Language: English
• Subjects: Catalysis; Chromatography; Ethylene; Oxidation
• ISSN: 0021-9517; 1090-2694
• DOI: 10.1016/j.jcat.2013.11.001

Ethylene oxide extracted from the surface was shown to be the primary reaction product. The zeolite modification by sodium strongly increases the selectivity, which attains 84% at the reaction temperature of -60°C. Display Omitted The stoichiometric oxidation of ethylene by anion radicals of [alpha]-oxygen, (FeIII -O [radical dot]- )[alpha] , created on the surface of non-modified and Na-modified FeZSM-5 zeolite was studied in the temperature range from 25 down to -60°C. Upon extraction, the products were identified using the gas chromatography, gas chromatography-mass spectrometry, and nuclear magnetic resonance. Unlike the oxidation of methane, the reaction S2 N4 +O[alpha] was shown to proceed without hydrogen abstraction from the ethylene (infrared spectroscopy data). It leads to O[alpha] addition over the double C[double bond; length as m-dash]C bond yielding the ethylene oxide (EO) primary product. Sodium modification of the zeolite strongly increases the selectivity for EO, which attains 80-84% at the reaction temperature of -60°C. A much lower selectivity at room temperature relates mainly to a secondary reaction of EO with ethylene leading to butyraldehyde. High epoxidizing selectivity of [alpha]-oxygen is discussed in relation to the mechanism of ethylene epoxidation on silver catalyst. [PUBLICATION ABSTRACT]