Preparation and characterization of NiO/MgO/Al2O3 supported CoPcS catalyst and its application to mercaptan oxidation

MgO/Al2O3 and NiO/MgO/Al2O3 solid bases were prepared by mixing method. The samples were characterized by X-ray diffraction (XRD), CO2 temperature-programmed desorption (CO2-TPD) and surface area measurements. After supported sulfonated cobalt phthalocyanine (CoPcS) the catalytic performance of these catalysts was evaluated in the mercaptan oxidation reaction. The effect of Mg/Al mole ratios on activity, crystal structure, basicity and stability in air was discussed. And the mechanism of the effect of NiO was identified. Results show that the base amount of MgO/Al2O3 increases with increasing Mg/Al mole ratio and catalyst with high Mg/Al mole ratio has a higher initial activity. NiO/MgO/Al2O3–CoPcS shows a higher initial activity and a much longer lifetime than MgO/Al2O3–CoPcS. When nickel oxide is doped into the MgO/Al2O3 support more crystal defects are generated, which increases the amount and types of basic sites.