We investigated the selective oxidation of hydrogen sulfide to elemental sulfur and ammonium thiosulfate by using Bi4V2-xSbxO11-y catalysts. The catalysts were prepared by the calcination of a homogeneous mixture of Bi2O3, V2O5, and Sb2O3 obtained by ball-milling adequate amounts of the three oxides. The main phases detected by XRD analysis were Bi4V2O11, Bi1.33V2O6, BiSbO4 and BiVO4. They showed good H2S conversion with less than 2% of SO2 selectivity with a feed composition of H2S/O2/NH3/H2O/He=5/2.5/5/60/27.5 and GHSV=12,000 h-1 in the temperature ranges of 220-260 ℃. The highest H2S conversion was obtained for x=0.2 in Bi4V2-xSbxO11-y catalyst. TPR/TPO results showed that this catalyst had the highest amount of oxygen consumption. XPS analysis before and after reaction
confirmed the least reduction of vanadium oxide phase for this catalyst during the reaction. It means that the catalyst with x=0.2 had the highest reoxidation capacity among the Bi4V2.xSbxO11.y catalysts.
vandenBrink PJ, Geus JW, "Selective Oxidation of Hydrogen Sulfide on a Sodium Promoted Iron Oxide on Silica Catalyst", US Patent 5,352,422, to VEG-Gasinstituut N.V. and Comprimo B.V., 1994