Phase cooperation of V2O5 and Bi2O3 in the selective oxidation of H2S containing ammonia and water

The selective oxidation of hydrogen sulfide containing excess water and ammonia was studied over vanadium oxide-based catalysts. The investigation was focused on the role of V2O5, and phase cooperation between V2O5 and Bi2O3 in this reaction. The conversion of H2S continued to decrease since V2O5 was gradually reduced by treatment with H2S. The activity of V2O5 was recovered by contact with oxygen. A strong synergistic phenomenon in catalytic activity was observed for the mechanically mixed catalysts of V2O5 and Bi2O3. Temperature-programmed reduction (TPR) and oxidation (TPO) and two bed reaction tests were performed to explain this synergistic effect by the reoxidation ability of Bi2O3.