Adsorption desulfurization performance of PdO/SiO2@graphene oxide hybrid aerogel: Influence of graphene oxide

Abstract

Preparation of PdO/SiO2@graphene oxide (GO) hybrid aerogels were carried out sol-gel method combined with atmospheric drying technology to study their adsorption performance for thiophenics and compared with PdO/SiO2. Scanning electron microscope (SEM), N2 adsorption-desorption isotherms, X-ray diffraction (XRD) analysis, X-ray photoelectron spectroscopy (XPS), and fourier transformation infrared spectroscopy (FT-IR) for samples were performed. The adsorption performance of PdO/SiO2@GO for thiophene were better than that of PdO/SiO2, attributed to that incorporation of GO increased the specific surface area and the Pd incorporation rate, where Pd2+ ions acted as the π-complexation and sulfur-metal (SM) bond adsorption active centers, as well as GO adsorbed thiophene by the π-π stacking effect. The adsorption capacities of PdO/SiO2@GO-1.0 for thiophene (TH), benzothiophene (BT) and dibenzothiophene (DBT) were 8.89, 9.3 and 12.6 mg-S/gads, respectively. The addition of GO in aerogels could improve the inhibition effect of toluene, cyclohexene and pyridine while decreased the inhibition effect of MTBE and H2O for the adsorption of thiophene, due to the π-π stacking effect and the hydrophobicity of GO, respectively. The adsorption process was spontaneous and exothermic, be well fitted by the apparent second-order kinetic model and dominated by chemical interaction. Pd/SiO2@GO-1.0 had a good solvent elution regeneration performance.