Preparation of ZrO2-supported MgO with high surface area and its use in mercaptan oxidation of jet fuel

A solid base, ZrO2-supported magnesia with high surface area (SA) has been prepared by impregnating hydrous zirconia with Mg(NO3)(2) solution and then calcining at 400 degrees C. MgO disperses on the surface of ZrO2 as a mono layer, which keeps ZrO2 in amorphous or tetragonal phase. TG-DTA results sh ow that the decomposition temperature of Mg(NO3)(2) in monolayer phase is l ower than that in crystalline phase and only monolayer-dispersed Mg(NO3)(2) turns into monolayer-dispersed MgO. The dispersion threshold of MgO on ZrO 2 determined by XRD is 0.25 g MgO/g ZrO2, corresponding to a surface covera ge near 1. The sample of MgQ/ZrO2 with the MgO content near the threshold p ossesses the highest SA (274 m(2)/g ZrO2), the largest number of basic site s and a larger share of sites with strong basicity. After supporting sulfon ated cobalt phthalocyanine (CoPcS), the catalyst displays a very good initi al activity of mercaptan oxidation for jet fuel (99% conversion of mercapta n to disulfide). (C) 2000 Elsevier Science B.V. All rights reserved.