The widely applied desulfurization technologies for flue gas are based on the acidic property of SO2. However, CO2 is also acidic, and the content of CO2 in flue gas is several orders higher than that of SO2; therefore, the interference of CO2 on desulfurization is a problem and an origin of secondary pollution. A reaction-enhanced sorption method is presented and tested in the present work. CO2 remained unchanged while the detrimental acidic species are oxidized and captured by adsorbent. The irreversibility of reactions and the large surface area of adsorbent guaranteed a complete capture of SO2. A breakthrough capacity of adsorbent as large as 323 mg/g was observed on a SBA-15 mesoporous adsorbent. The by-products produced at regeneration are of market value, and the desulfurization technique does not yield secondary pollution.