Synthesis of Al2O3, MgO and MgAl2O4 by solution combustion method and investigation of performances in partial oxidation of methane

Abstract

Al2O3, MgO and MgAl2O4 nanocrystalline and mesoporous materials were prepared by simple solution combustion synthesis using urea and metal nitrates and the effect of metal nitrate/urea ratio was investigated. The metal oxides that were found suitable for catalytic purposes were tested in catalytic partial oxidation of methane (CPOM). It was observed that the oxidizer/fuel ratio could affect the structure phase, crystallinity and morphology of the synthesized materials. gamma-Al2O3 was obtained when the equivalence ratio was 2, and at lower ratios, the obtained phase was alpha-Al2O3. The cubic MgO phase was obtained at each ratio but the material yield was low below the equivalence ratio of 4. Highly crystalline MgAl2O4 was obtained at fuel-rich conditions only. 10% (wt.) Ni loaded MgAl2O4-2 and MgO-4 showed high activity (>90% CH4 conversion) and product selectivity (>98% H-2 and CO selectivity) at 800 degrees C under 157,5001 kg(-1) h(-1). (C) 2019 Elsevier B.V. All rights reserved.