Physicochemical properties and desulfurization activities of metal oxide/biomass-based activated carbons prepared by blending method

Column activated carbons were prepared from walnut shell chars and transition metal oxide powders (i.e. Co₂O₃, Ni₂O₃, CuO and V₂O₅) with blending method. Samples were characterized by N₂ adsorption–desorption, X-ray diffraction, X-ray photoelectron spectroscopy and Fourier-transform infrared spectroscopy. The texture properties of all modified activated carbons with metal oxides dosage of <5 wt% did not change evidently. The basic functionalities of these activated carbons increased relative to blank carbon. Moreover, metal species with different oxidation states coexisted on the modified activated carbons. The optimal dosage of all metal oxides was 2 wt%. The sulfur capacities of these modified activated carbons were 7.7–46.0 % higher than that of blank activated carbon and the highest occurred for V₂O₅ modified activated carbon. The improved desulfurization performance was mainly attributed to the higher catalytic activity of the active metal oxides formed in the presence of O₂ during the desulfurization process.