Development of bimetallic and trimetallic oxides doped on molybdenum oxide based material on oxidative desulfurization of diesel

Abstract

Catalytic oxidative desulfurization (Cat-ODS) activities of thiophenic sulfur were compared using alumina supported of mono-, bi- and trimetallic oxide molybdena based catalysts, prepared by incipient wetness impregnation. The aim of this study was to inquire on the possibility of supported trimetallic oxide catalysts for deep Cat-ODS process. The prepared catalysts were characterized by nitrogen adsorption, X-ray diffraction, field emission scanning electron microscopy and transmission electron microscopy, and tested in the ODS of model thiophene, dibenzothiophene and 4,6-dimethyldibenzothiphene, as well as on commercial and crude diesel. It was found that the addition of dopant and co-dopant toward MoO3/Al2O3 catalysts increased significantly the selectivity of catalytic performance in the order: mono- < bi- < trimetallic oxide. Under these optimum conditions: TBHP/sulfur ratio of 3, 2.13%V/4.08%W/16.07%MoO3/Al2O3 (0.2 g), temperature of 60 °C, 30 min of reaction, and complete removal of model organosulfur compounds were obtained. In addition, >90% of sulfur was removed in both commercial and crude diesel under similar reaction conditions. Reproducibility test showed that the catalyst has higher catalytic activity and could be repeatedly used with little change after five cycles.