The effects of ammonium sulfate and sulfamic acid on the surface acidity of sulfated zirconia

Abstract

In this work, sulfated zirconia (SZ) was prepared by a solvent-free method, ammonium sulfate ((NH4)2SO4) and sulfamic acid (NH2SO3H) were as sulfur sources, respectively. The resulting catalysts were characterized by powder X-ray diffraction (XRD), thermogravimetric analysis and differential scanning calorimetry (TGA-DSC), N2 adsorption–desorption isotherms, inductively coupled plasma (ICP) and pyridine-FTIR. The characterization of the catalysts revealed that SZ prepared with (NH4)2SO4 as sulfur source contained more Lewis acid sites and less Brønsted acid sites. The effects of sulfur sources on the catalytic activity of catalysts were studied. Catalytic testing showed that SZ prepared with (NH4)2SO4 as sulfur source had a better catalytic performance for removing trace olefins from aromatics. Keywords: Aromatics, Olefins, Sulfur sources, Sulfated zirconia