Effect of trace oxygen on smelter off-gas reduction desulphurization process over FeSx/γ-Al2O3 catalysts

Effects of trace oxygen on iron sulphides-supported catalysts (FeS x /γ-Al 2 O 3 ) were evaluated through smelter off-gas reduction process for sulphur synthesis. Catalytic performance was evaluated under different oxygen content conditions. The properties of fresh and used catalysts were investigated by means of X-ray diffraction (XRD), thermogravimetry-differential thermal analysis (TG-DTA), X-ray photoelectron spectroscopy (XPS), and elemental analysis and relationships of active phases and activity were analyzed. The relationship between different active crystal crystals (FeS x , FeS 2 , Fe, FeO, γ-Fe 2 O 3 ) and SO 2 /O 2 adsorption and conversion was investigated. The mechanism of oxygen influence on the FeS x /γ-Al 2 O 3 surface was given and the lifetime of the catalyst in the reaction atmosphere close to real smelter off-gas after dust and oxygen removal steps containing trace oxygen (0.5 O 2 v/v.%) was explored.