Abstract:
In this research, the characteristics and catalytic performances of V2O5catalysts supported on mixed oxides CeO2-MO2 (M = Ti, Si, Zr) as compared to the commercial CeO2 supported ones were studied in the selective catalytic oxidation of H2S in biogas to sulfur at 130oC. The mixed-oxide supports were prepared by co-precipitation method with 3 wt.% vanadium loading by wet impregnation method. From the XRD and Raman spectroscopy results, all the catalysts exhibited high dispersion of V2O5 on the supports with the 1:1 molar ratio CeO2-SiO2 mixed oxide showed the highest conversion of H2S at ̴ 73% and low selectivity of SO2 at ̴ 19 ppm. From the O2-TPD results, the strong interaction between V2O5 and support produced more oxygen vacancies and as a consequence, the V2O5/CeO2-SiO2 exhibited low temperature desorption peak of chemically adsorbed oxygen suggesting a rapid restoration of catalyst from V4+ to V5+ state, which was directly related to the limiting step of the selective oxidation of H2S. As a consequence, the catalyst activity could be enhanced.
