Development of vanadium-based mixed oxide catalysts for selective oxidation of H2S to sulfur

Various vanadium-based binary and multi-metallic oxides were prepared and their catalytic activities for the selective oxidation of H2S to elemental sulfur were tested. Because the deactivation of vanadium-based catalysts originated from a relatively slow Fate of reoxidation of the reduced vanadium oxide [PhD thesis, Pohang University of Science and Technology, 2000], the focus was given to increase the redox ability, especially in the reoxidation step. Stable and improved activity was observed in BiVOx, TiVOx, and ZrV2O7 at 250 degreesC, but TiVOx was the only catalyst that could maintain its activity below 250 degreesC. Much higher activity was observed when VOx/TiO2 became multi-metallic by the incorporation of Fe, Cr, and Mo. TPR-TPO, microbalance, and XPS techniques were used to explain the redox properties of VOx/SiO2, VOx/TiO2, and V-Fe-Cr-Mo-O-x/TiO2 catalysts in the reoxidation step. (C) 2001 Elsevier Science B.V. All rights reserved.