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

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°C. MgO disperses on the surface of ZrO2 as a monolayer, which keeps ZrO2 in amorphous or tetragonal phase. TG-DTA results show that the decomposition temperature of Mg(NO3)2 in monolayer phase is lower than that in crystalline phase and only monolayer-dispersed Mg(NO3)2 turns into monolayer-dispersed MgO. The dispersion threshold of MgO on ZrO2 determined by XRD is 0.25 g MgO/g ZrO2, corresponding to a surface coverage near 1. The sample of MgO/ZrO2 with the MgO content near the threshold possesses the highest SA (274 m2/g ZrO2), the largest number of basic sites and a larger share of sites with strong basicity. After supporting sulfonated cobalt phthalocyanine (CoPcS), the catalyst displays a very good initial activity of mercaptan oxidation for jet fuel (99% conversion of mercaptan to disulfide).