Abstract:Mechanism and influencing factors on preparation of sulphur by sulfur dioxide electrochemical reduction process with 316L stainless steel as cathode were studied. Reduction mechanism of sulfur dioxide on 316L stainless steel electrode was studied by cyclic voltammetry and chronocoulometry methods. It was proposed that sulfur dioxide experienced reduction process of four electrons and four protons. Effects of current density and acid concentration of cathode solution on electrochemical reduction process were investigated in ionic membrane reactor. The results show that conversion rate of sulfur dioxide to sulfur is 73.42%, space-time output is 0.64 kg/(m3?h), and unit energy consumption is 9.64 kWh/kg under the conditions including sulfur dioxide concentration of 5 g/L, sulfuric acid concentration of 0.5 mol/L, current density of 126.98 A/m2, and electrolysis duration of 3 h.