Synthesis and Desulfurization Performance of Functional Silica Gel Modified by Polymeric 1-Vinyl-3-ethylimidazolium Tetrafluoroborate Ionic Liquids

Abstract

Polymeric 1-vinyl-3-ethylimidazolium tetrafluoroborate ionic liquids modified microspheres of silica gel were prepared by free radical polymerization in toluene. Characterization with Fourier transform infrared (FTIR), elemental analysis, scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), gel permeation chromatography (GPC), thermogravimetric analysis (TGA), and 13 C, 29 Si magic angle spinning (MAS) nuclear magnetic resonance (NMR) demonstrated that 1-vinyl-3-ethylimidazolium tetrafluoroborate had successfully loaded on the surface of silica gel and formed a stable polymer coating. Furthermore, to detect the potential desulfurization performance, a series of experiments of model fuel desulfurization with polymeric ionic liquid modified silica gel had been carried out. The desulfurization efficiency of modified silica gel was investigated by removing 2-methylthiophene, benzothiophene, and dibenzothiophene from model fuel ( n -heptane/2-methylthiophene, benzothiophene, and dibenzothiophene) under tested conditions. It was shown that the modified silica gel exhibited remarkable desulfurization capacity for aromatic S-containing compounds and the sulfur removal selectivity followed the order of 2-methylthiophene < benzothiophene < dibenzothiophene due to the different density aromatic π-electrons.