Commercial coke was modified by H2SO4 and (NH4)(2)S2O8 to enhance the adsorption and its catalytic activity, respectively. The properties of coke samples were characterized by Brunauer Emmett Teller analysis, Fourier transform infrared spectroscopy, scanning electron microscopy-energy-dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, and in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) analysis. The activity performance was examined in a fixed bed reactor, and the effects of temperature, O-2, H2O, and CO2 were investigated. The desulfurization performance of modified activated coke was considerably enhanced by treatment with (NH4)(2)S2O8. This is due to the existence of oxygen and nitrogen functional groups and the enhanced porous structure of modified activated coke. The DRIFTS behavior of SO2 suggested that the presence of O-2 greatly promotes SO2 adsorption and improves SO2 oxidation and retention on activated coke. that the modification by (NH4)(2)S2O8 significantly improves SO2 oxidation and retention on activated coke.