Carbon mono and dioxide hydrogenation over pure and metal oxide decorated graphene oxide substrates: insight from DFT

Abstract

Based on first principles density functional theory calculations we explore the energetics of the conversion of carbon mono and dioxide to methane over graphene oxide surfaces. Similar to the recently discovered hydration of various organic species over this catalyst, the transfer of hydrogen atoms from hydroxyl groups of graphene oxide provide a step by step transformation hydrogenation of carbon oxides. Estimated yields of modeled reactions at room temperature are about 0.01% for the carbon mono and dioxide. For the modeling of graphene oxide/metal oxide composites, calculations in the presence of MO_2 (where M = V, Cr, Mn, Fe) have been performed. Results of these calculations demonstrate significant decreases of the energy costs and increases of reaction yields to 0.07%, which is comparable to the efficiency of these reactions over platinum and ruthenium-based photocatalysts. Increasing the temperature to the value 100C should provide the total conversion of carbon mono and dioxides.