Highly Selective Deep Desulfurization of a Model Gasoline on Amine-Modified SiO₂ Hybrid Aerogel

Abstract

Amine-modified SiO 2 hybrid aerogel desulfurization adsorbents with varied Si/N molar ratios (SiO 2 -NH 2 -n) were prepared via the sol−gel method followed by the atmospheric drying technique. SiO 2 -NH 2 -n aerogels were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), in situ Fourier transform infrared (FT-IR), and N 2 adsorption−desorption. The desulfurization performances of SiO 2 -NH 2 -n were studied by the batch and breakthrough adsorption experiments. SiO 2 -NH 2 -n exhibited an obvious improvement in adsorption capacity for thiophenics compared with SiO 2 aerogel due to the hydrogen bonding between thiophenics and amino groups. Among them, SiO 2 -NH 2 -8 had the best performance, and the adsorption capacities for thiophene, benzothiophene, and dibenzothiophene were 6.8, 9.5, and 10.2 mg S/g ads , respectively. No effect of toluene and cyclohexene on the adsorption of SiO 2 -NH 2 -8 for thiophene was observed. The equilibrium adsorption data of SiO 2 -NH 2 -8 for thiophene were well fitted by the Freundlich model, indicating that multilayer adsorption occurred on the heterogenetic surface of SiO 2 -NH 2 -8. The kinetic adsorption data of SiO 2 -NH 2 -8 for thiophene could correlate properly with the pseudo-second-order kinetic model, suggesting that the rate-controlling steps involve surface adsorption. The saturated SiO 2 -NH 2 -8 could be regenerated completely via heating at 393 K for 12 h, and the regenerated SiO 2 -NH 2 -8 afforded 100% breakthrough adsorption capacity for thiophene.

Application of Microscopic Highly Hydrophilic Silica-Based Nanocomposites with High Surface Exposure in the Efficient Identification of Intact N-Glycopeptides

“…In the literature, the amino content is usually not higher than 2 mmol g −1 . 27,28 These results manifested that the present synthesis method had the superiority to synthesize the SiO 2based materials with higher contents of amino groups. With the increase of the 3-aminopropyl mole amount from 0 to 40 mol %, the percentage of silicon species in the bulk phase decreased from 62.6% to 20.4%, while the percentage of silicon species on the surface increased from 37.4% to 79.6%.…”