Synthesis of metal-oxide pillared montmorillonite clay for the selective catalytic oxidation of H 2S

Abstract

In the present work, titania-pillared clay (Ti-PILC) and zirconia-pillared clay (Zr-PILC) were synthesized, and their catalytic performance was studied for the selective oxidation of H 2S to elemental sulfur. The obtained pillared clays (PILCs) were characterized by X-ray fluorescence spectroscopy (XRF), infrared (FTIR) spectroscopy, BET surface area measurements, X-ray photoelectron spectroscopy (XPS), UV–vis-diffuse reflectance spectroscopy (UV–vis-DRS), temperature-programmed desorption of ammonia (NH 3-TPD), and thermogravimetric (TG) analysis. The reaction tests were carried out in a continuous flow fixed-bed reactor at temperature ranging from 220 to 300 °C. The conversion of H 2S increased with increasing temperature for all PILCs while the selectivity to SO 2 remained almost constant. The good catalytic performance of the metal-oxide pillared clays may be due to the high surface area and the presence of Brönsted and Lewis acid sites.