Performance of vanadium–molybdenum mixed oxide catalysts in selective oxidation of hydrogen sulfide containing excess water and ammonia

The selective oxidation of hydrogen sulfide containing excess water and ammonia was studied over V2O5/TiO2 and Mo–V–O/TiO2 catalysts. Ammonia reacted either with H2S or SO2, produced from the oxidation of H2S. Water vapor promoted the reaction of ammonia and SO2. Mo–V–O/TiO2 catalysts showed very high H2S conversion without any considerable emission of SO2. Temperature-programmed studies [temperature-programmed reduction (TPR) and temperature-programmed oxidation (TPO)], X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) analyses revealed that the high catalytic performance of Mo–V–O/TiO2 catalysts originated from the high redox capacity of vanadium molybdate phase.