Green Synthesis of Graphite Oxide as Metal free Catalyst for Petrochemicals Production

Abstract

Graphite oxide was synthesized by the modified Hummer’s method. The degree of the oxidation of the graphite was systematically controlled via the oxidation time, KMnO₄ : Graphite wt. ratio and the addition of the phosphoric acid to the oxidation media. The Physicochemical properties of the synthesized graphite oxide are investigated by using different techniques ; XRD,  FTIR, zeta potential, and TEM. It was found that the structure of the expanded graphite can be easily and remarkably disordered by oxidation. Three phases of interlayer distances were identified at 3.4 , 4 and 6A⁰ , specified for the pristine graphite, intermediate and the fully expanded graphite oxide respectively  These phases were cooresponding to the compositions : epoxide, carboxyl and hydroxyl groups respectively . as confirmed by FTIR.

The catalytic activity of the prepared graphite oxide samples was tested for petrochemical production from the ethanol conversion reaction at different reaction temperature 100-250^oC and resulted pressure ranging  40-92 atm . The converted products were mainly composed of  acetone, ethylene, acetaldehyde, diethylether, and heavyhydrocarbons( >c). Acetone was found to be the main product at all reaction temperatures with selectivity ‘‘53-94%’’. XRD and TEM analyses of the prepared samples confirmed  the transformation of  the prepared graphite oxide into graphene like material at reaction temperature 250^oC.