Catalytic oxidation of SO2 by novel Mn/copper slag nanocatalyst and optimization by Box-Behnken design

Abstract

Catalytic oxidation of SO2 by novel Mn/copper slag nanocatalystIn this research, the oxidation of sulfur dioxide (SO₂) gases is investigated by Mn/copper slag nanocatalyst (Mn/CS) as a novel catalyst at low temperatures. The removal of SO₂ gas from industrial exhaust is important to reduce environmental pollution. The SO₂ gas in aqueous solution was oxidized and converted to sulfuric acid as an energy source by Mn/CS in the semi-batch reactor (SBR). The characterization of the catalyst was studied using X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDX), field emission scanning electron microscopy (FESEM), and Fourier transform infrared spectroscopy (FTIR), simultaneous thermal analysis (thermogravimetry/differential thermal analysis) STA (TG/DTA) techniques, X-ray fluorescence microscopy (XRF) and BET surface area. A Box-Behnken design (BBD) was used for the optimization of influencing factors such as the amount of nanocatalyst, the temperature and the reaction time in the oxidation of SO₂. The graphical counter plots and response surface were used to determine the optimum conditions. The results showed that the nanocatalyst had the most significant effect on SO₂ oxidation compared with the other two variables. Temperatureâ=â283 K, Mn/CS amountâ=â6 g/L and Timeâ=â60 min were determined as maximum efficiency for oxidation of SO₂.