Dry Reforming of Methane on Carriers and Oxide Catalysts to Synthesis-Gas

Abstract

The catalytic activity of carriers: θ‒Al₂O₃, γ‒Al₂O₃, 5A, 4A, 3A and 13X and the oxides of metals of variable valency ‒ NiO, La₂O₃, CuO, MoO₃, MgO, V₂O₅, WO₃, CoO, Cr₂O₃, ZnO, ZrO₂, CeO₂, Fe₂O₃, supported on the effective carrier γ‒Al₂O₃ by the method of capillary impregnation of the support with solutions of nitric salts of metals were investigated in the process of carbon dioxide conversion of methane (DRM). The optimal technological regimes for the process were: the reaction temperature -800 °C, the space velocity of the initial reactants ‒ 1500 h^-1 with a methane to carbon dioxide ratio equal to 1. It was found that among the studied catalysts the highest activity is shown by the NiO/γ‒Al₂O₃ catalyst, where the yields of hydrogen and carbon monoxide reaches 45.4 and 42.4% by volume, respectively, when methane conversion is 89%. The XRF method showed that the content of alumina and nickel oxide after the reaction remained unchanged at 96.7 and 3.0%, respectively. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), small angle X-ray scattering (XRS) determined that nickel-containing NiO/γ‒Al₂O₃ catalyst form nickel nanoparticles (6.4‒10 and 50‒150 nm) and a uniform their distribution on the surface of the carrier takes place. These physical chemical characteristics have a positive effect on the activity of NiO/γ‒Al₂O₃ catalyst in the process of carbon dioxide conversion of methane to synthesis gas.