Combined magnesia, ceria and nickel catalyst supported over γ-alumina doped with titania for dry reforming of methane

Abstract

This study investigated dry reforming of methane (DRM) over combined catalysts supported on γ-Al2O3 support doped with 3.0 wt. % TiO2. Physicochemical properties of all catalysts were determined by inductively coupled plasma/mass spectrometry (ICP-MS), nitrogen physisorption, X-ray diffraction, temperature programmed reduction/oxidation/desorption/pulse hydrogen chemisorption, thermogravimetric analysis, and scanning electron microscopy. Addition of CeO2 and MgO to Ni strengthened the interaction between the Ni and the support. The catalytic activity results indicate that the addition of CeO2 and MgO to Ni did not reduce carbon deposition, but improved the activity of the catalysts. Temperature programmed oxidation (TPO) revealed the formation of carbon that is mainly amorphous and small amount of graphite. The highest CH4 and CO2 conversion was found for the catalyst composed of 5.0 wt. % NiO-10.0 wt. % CeO2/3.0 wt. %TiO2-γ-Al2O3 (Ti-CAT-II), resulting in H2/CO mole ratio close to unity. The optimum reaction conditions in terms of reactant conversion and H2/CO mole ratio were achieved by varying space velocity and CO2/CH4 mole ratio.