High adsorptive performance of SiO2@Chitosan oligosaccharide hybrid aerogels for thiophenics in model fuels and aromatic products

SiO 2 @CSO-n (Chitosan Oligosaccharide) hybrid aerogels with different amount of CSO were simply prepared by sol-gel method combined with atmospheric drying technology, due to the slower hydrolysis rate of CSO. These hybrid aerogels were used for the adsorptive removal of thiophenics from model fuels and aromatic products. With respect to SiO 2 aerogel, the adsorptive desulfurization performance of SiO 2 @CSO-n hybrid aerogels improved significantly, owing to the —NH 2 and —NH 3 + groups on the surface acted as the adsorption active centers for thiophenics based on the hydrogen bond. With the increase of CSO content, the adsorption capacity of SiO 2 @CSO-n for thiophene firstly increased and then decreased, among them, SiO 2 @CSO-200 preformed the best, up to 10.88 mg-S/g ads for dibenzothiophene, 8.84 mg-S/g ads for benzothiophene, 7.48 mg-S/g ads for thiophene. For SiO 2 @CSO-200, the obvious competitive adsorption of aromatics against thiophene occurred only in aromatic products. After the fourth regeneration for used SiO 2 @CSO-200, the breakthrough adsorption capacity of thiophene could be completely recovered by the heating treatment regeneration mode while only recovered 72% using the solvent solution regeneration method. The equilibrium adsorption and adsorption kinetic data were better fitted by Freundlich adsorption isotherm model and pseudo-second-order kinetic model, respectively, and the adsorption process was spontaneous and exothermic, with a decrease freedom degree of system. Graphical Abstract Highlights Simple preparation of SiO 2 @CSO (Chitosan oligosaccharide) hybrid aerogels. The high adsorption desulfurization performance of SiO 2 @CSO for fuels and aromatics. The —NH 2 /NH 3 + groups of SiO 2 @CSO acted as adsorption active centers for thiophenics. The formation of hydrogen bond between the —NH 2 /NH 3 + groups and thiophenics.