Synthesis and characterization of graphene oxide supported cobalt (II) tetrasulfophthalocyanine as an efficient heterogeneous nanocatalyst for mercaptans oxidation from gasoline

Abstract

In the present study, graphene oxide-supported cobalt (II) tetrasulfophthalocyanine (CoTsPc-GO) was synthesized using the incipient wetness impregnation assisted [Formula: see text]–[Formula: see text] assembling method. Applications for this material were investigated for ethyl mercaptan, [Formula: see text]-propyl mercaptan and [Formula: see text]-butyl mercaptan oxidation from fluid catalytic cracking (FCC) gasoline in a fixed bed reactor. The synthesized CoTsPc-GO catalysts were characterized using UV-vis spectroscopy, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Raman spectroscopy analysis, field emission scanning electron microscopy (FESEM), energy dispersive X-ray (EDAX), thermogravimetric and differential thermal analysis (TGA-DTA), inductively coupled plasma optical emission spectroscopy (ICP-OES), and transmission electron microscopy (TEM). The effect of cobalt (II) tetrasulfophthalocyanine (CoTsPc) content (0–0.34 g), catalyst dosage (0.02–0.12 g) and temperature (30–40∘ C) on the performance of CoTsPc-GO catalysts were investigated during the Merox process. The stability and reusability of CoTsPc-GO catalyst for mercaptans oxidation were also tested. The obtained results revealed that the maximum mercaptan oxidation during the Merox process was obtained in CoTsPc-GO of 0.34 g, catalyst content of 0.1 g and a temperature of 40∘ C with ethyl mercaptan, [Formula: see text]-propyl mercaptan and [Formula: see text]-butyl mercaptan conversions of 99.9, 98.5 and 97.0%, respectively. The potential of CoTsPc-GO catalyst was investigated for further mercaptans oxidation. The results were compared to those obtained with an industrial impregnated active charcoal catalyst and a CoPc catalyst. The obtained results demonstrated the higher capability of CoTsPc-GO catalyst for mercaptans oxidation from FCC gasoline.