VANADIUM-BASED MIXED-OXIDE CATALYSTS FOR SELECTIVE OXIDATION OF HYDROGEN-SULFIDE TO SULFUR

The selective oxidation of hydrogen sulfide to sulfur was studied over three vanadium-based mixed-oxide catalysts, including the binary oxid es of vanadium-molybdenum, vanadium-bismuth, and vanadium-magnesium. T he catalytic reaction was carried out in a fixed-bed reactor in the te mperature range 200-300 degrees C. Strong synergistic phenomena in cat alytic activity and selectivity were observed for the binary oxides. U nder identical reaction conditions, the performances of the binary oxi de catalysts within certain composition ranges were superior to those of the corresponding single-oxide catalysts. These synergistic phenome na suggest that the new compounds Mo6V9O40, BiVO4/Bi4V6O21, and MgV2O formed in the binary oxides are much better than the corresponding sin gle-oxide catalysts for the selective oxidation of hydrogen sulfide. T he maximum sulfur yield obtained with the vanadium-based binary mixed- oxide catalysts was 97%, which was much higher than that obtained with pure vanadium oxide (78%).