Oxidation of Mercaptans from Light Oil Sweetening by Fe2O3/MgO/Al2O3 Supported CoPcS Catalyst

MgO/Al2O3 and Fe2O3/MgO/Al2O3 solid bases were prepared through mixing method. After sulfonated cobalt phthalocyanine (CoPcS) being supported on these solid bases, the catalytic performance of these catalysts was evaluated by means of mercaptan oxidation reaction. The samples were characterized by X-ray diffraction (XRD), CO2 temperature-programmed desorption (CO2-TPD), FTIR spectroscopy, and X-ray photoelectron spectroscopy (XPS). Investigation was focused on the effect of Fe2O3 on activity, crystal structure, basicity, and stability of the catalyst and also on the role of Fe2O3 in the mercaptan oxidation processes. Test results have shown that the Fe2O3/MgO/Al2O3-CoPcS catalyst has a higher initial activity and a much longer service life than the MgO/Al2O3-CoPcS catalyst. The increased types of basic sites coupled with an enhanced oxidation ability resulted from the addition of Fe2O3 have contributed to the improvement of the catalytic activity of the MgO/Al2O3-CoPcS catalyst.