Selective catalytic oxidation of H_2S to elemental sulfur over V_2O_5/Zr-pillared montmorillonite clay

摘要

The performance of vanadia-doped zirconia-pillared clay (V/Zr-PILC) for the selective catalytic oxidation of H_2S was investigated in this study. A series of vanadia-doped zirconia pillared clays (V/Zr-PILCs) with various amounts of vanadia were prepared and characterized using X-ray diffraction (XRD), surface area-pore volume measurements, chemical analysis, infrared (FTIR) spectroscopy, UV-vis-diffuse reflectance spectroscopy (UV-vis-DRS), X-ray photoelectron spectroscopy (XPS), and thermogravimetric (TG) analysis. V/Zr-PILCs showed better catalytic performance than Zr-PILC at temperatures ranging from 220-300 ℃ without any considerable SO_2 emission. The H_2S conversion over V/Zr-PILCs increased with increasing vanadia content up to 6 wt%. However, it decreased at higher vanadia loadings due to the decrease of surface area and to the formation of the crystalline V_2O_5 phase. The results of a regeneration experiment using 6 wt% V/Zr-PILC catalyst showed good reproducibility in its catalytic activity, even through five successive sulfidation-regeneration cycles at 280 ℃.