Catalytic Reduction of SO2 with CO over LaCoO3 Perovskites Catalysts: Effect of Fe Doping and Pre-Sulfurization

SO2 emissions are a major source of air pollution, and the catalytic reduction of SO2 to elemental sulfur by CO represents a promising solution. This study investigates the effects of Fe doping and pre-sulfurization on the catalytic performance of LaCoO₃ perovskite catalysts. A series of Fe-doped LaCoO3 perovskites were synthesized via the sol–gel method and evaluated for the catalytic reduction of SO2 by CO. The results showed that LaCo0.8Fe0.2O3 exhibited the highest catalytic performance, achieving 84.0% SO2 conversion at 500 °C. The oxygen-free sulfurization (OFS) treatment compared with oxygen-assisted sulfurization (OAS) treatment significantly enhanced the activity, reaching a SO2 conversion of 95.9% from 80.0% at 450 °C with the lower byproduct generation. Characterization analyses demonstrated that the OFS treatment facilitated the formation of active sulfur species and oxygen vacancies on the catalyst surface while also enhancing the adsorption capacity of the catalyst for the reactant gases. These factors were identified as key contributors to the improved catalytic performance, driven by the combination of redox and carbonyl sulfide (COS) intermediate mechanism. The findings suggest that the OFS treatment is an effective strategy to improve the catalytic reduction of SO2 by CO, offering a more environmentally friendly solution for SO2 emission control through resource utilization.