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

Authors

• Abdol Hossein Khangah ¹
• Mohammad Javad Sarraf ²
• Habib Ale Ebrahim ³
• Masoumeh Tabatabaee * ⁴

1. Department of Chemical Engineering, Yazd Branch, Islamic Azad University, Yazd, Iran.
2. Department of Chemical and Polymer Engineering, Faculty of Engineering, Yazd University, Yazd, Iran.
3. Department of Chemical Engineering, Amirkabir University of Technology, Tehran, Iran.
4. Department of Chemistry, Faculty of Science, Yazd Branch, Islamic Azad University, Yazd, Iran

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.

Keywords

• SO2 reduction.
• Catalytic activity
• Ternary Cerium/Lanthanum/Iron oxides
• Response Surface Method
• Catalyst surface area