Mechanism of extractive/oxidative desulfurization using the ionic liquid inimidazole acetate: a computational study

Hanlu Wang; Mingsheng Xu; Rujin Zhou

doi:10.1007/s00894-017-3230-2

Mechanism of extractive/oxidative desulfurization using the ionic liquid inimidazole acetate: a computational study

J Mol Model. 2017 Feb;23(2):54. doi: 10.1007/s00894-017-3230-2. Epub 2017 Feb 4.

Authors

Hanlu Wang¹, Mingsheng Xu², Rujin Zhou³

Affiliations

¹ College of Chemical Engineering, Guangdong University of Petrochemical Technology, Maoming, 525000, People's Republic of China. wanghlu@mail2.sysu.edu.cn.
² College of Chemical Engineering, Guangdong University of Petrochemical Technology, Maoming, 525000, People's Republic of China.
³ College of Chemical Engineering, Guangdong University of Petrochemical Technology, Maoming, 525000, People's Republic of China. rujinzhou@126.com.

PMID: 28161783
DOI: 10.1007/s00894-017-3230-2

Abstract

The dual role of the ionic liquid 1-butyl-3-methyl-imidazolium trifluoroacetic acid ([C₄mim]TFA) as an extractant for thiophene (TH) and a catalyst for the oxidation of TH was explored at the molecular level by performing density functional theory (DFT) calculations. The calculated interaction energies demonstrated why [C₄mim]TFA is a better extractant for thiophene sulfone (THO₂) than for TH. Two pathways were proposed for the oxidation of TH to THO₂ with [C₄mim]TFA acting as a catalyst. In the dominant pathway, a peracid is formed which then oxidizes TH to the sulfoxide and sulfones. The presence of [C₄mim]TFA was found to greatly reduce the barrier to the oxidative desulfurization (ODS) of TH using H₂O₂ as an oxidant. Graphical Abstract Possible reaction mechanisms of TH with the aid of [C4mim]TFAᅟ.

Keywords: DFT; Desulfurization; Extraction/oxidation; Imidazole acetate; Ionic liquid.