Synthesis of ternary Ce2O3/La2O3/Fe3O4 oxides as a potential catalyst for SO2 reduction by CH4 to sulfur

Abstract

In this study, ternary mixed metal oxide (Ce₂O₃/La₂O₃/Fe₃O₄) catalysts were synthesized for reduction of SO₂ to sulfur by CH₄. The response surface method (RSM) was used to optimize the synthesis conditions. The XRD, FESEM, BET, BJH, EDX and NH₃-TPD analyses were performed to characterize the synthesized catalysts. The optimum conditions were obtained for an activated catalyst with 8 wt% La, 16 wt% Fe, and calcination temperature of 650°C. The highest surface area was found to be 71.7 m².g^-1. The validation tests proved that the predicted model was well fitted with the experimental data. Furthermore, the SO₂ conversions were compared at various temperatures (550-800 °C) and it was found that the highest reactivity was found for optimum Ce₂O₃/La₂O₃/Fe₃O₄ catalyst. The highest SO₂ conversion was found to be 93% at 800 °C. The catalytic results showed that optimum ternary Ce₂O₃/La₂O₃/Fe₃O₄ catalyst had a better performance compared to pure cerium oxide.