Novel and simple one-pot method for the synthesis of titanium modified-CMK-3 applied in desulfurization of refractory oeganosulfur compounds.

Abstract

Ti-CMK-3 carbon mesoporous was prepared using a novel synthesis method. This new method avoids the hard template synthesis used commonly. The method developed here, allows reducing time, energy consumption and cost. Our primary aim in this work is to evaluate the ODS activity of the Ti-modified mesoporous carbon CMK-3, synthesized by the short time method, in order to achieve total removal of sulfur compounds from diesel fuel. The catalytic oxidation of the sulfur compound with hydrogen peroxide was carried out in a glass batch reactor, equipped with a magnetic stirrer, a thermometer and a condenser. In a typical run, the solid catalyst (60 mg) was suspended under stirring (750 rpm) in 20 mL of a solution of 500 ppm of S as DBT (or other) in acetonitrile. Then, appropriate amount of 30% aqueous H2O2 was added at constant temperature. The experiments were performed in a three-phase liquid-liquid-solid (L (oil) –L (solvent) –S (catalyst)) system, acetonitrile was used as solvent and dodecane as oil phase. Solution samples were recovered at various times. The products were analyzed by GC HP 5890 Series II with a HP-5 column and connected to FID and PFPD detectors, after filtration and eventually decantation step. The products were confirmed using a Shimadzu GCMS. Structural and textural characterization of the titanium modified-mesoporous carbon was performed by N2 adsorption, XRD, UV-Vis-DRS, XPS, Raman spectroscopy and TEM. The characterization results indicated that the textural and structural properties of the material synthesized by the short time method are comparable with the properties of the material prepared by the hard template method. Ti modified-mesoporous carbon was synthesized by different methods in order to prepare catalysts to be tested in the oxidative desulfurization (ODS) of sulfur compounds. The good performance and stability of the catalyst prepared using a novel synthesis method was attributed to well dispersed anatase nanospecies over the high area mesoporous carbon. Main advantage of the present study is the reduction of time and cost in the synthesis of the new material and the applicability for ODS reactions.