Co-promoted MoO3 nanoclusters for hydrodesulfurization

Abstract

In this paper, we report the synthesis of ultrasmall Co-promoted MoO₃ nanoclusters (∼2 nm) supported over γ-Al₂O₃ possessing an increased number of Mo edge atoms, using colloidal synthesis for hydrodesulfurization reaction. A three-step synthesis methodology was followed: in the first step, Co-promoted MoO₃ nanoclusters (∼2 nm) were synthesized using oleic acid and oleylamine as capping agents. In the second step, oxide nanoclusters were supported over γ-Al₂O₃ and then calcined. In the third step, supported metal oxide nanoclusters were sulfided using dimethyl disulfide as a sulfiding agent. These catalysts show enhanced catalytic activity towards hydrodesulfurization of dibenzothiophene compared to those prepared by using the conventional metal impregnation method due to the presence of a higher number of Mo edge atoms (36%), easier reducibility and sulfidability. The catalysts were characterized by using transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and temperature programmed reduction (TPR) analysis.