Synthesis of Highly Dispersed Nanosized NiO/MgO-Al₂O₃ Catalyst for the Production of Synthetic Natural Gas with Enhanced Activity and Resistance to Coke Formation

Abstract

Nickel nanoparticles supported on MgO-Al2O3 and Al2O3 were synthesized by an impregnation method using dinitrobisethylenediamine nickel and nickel nitrate hexahydrate as precursors and were used as catalysts for CO methanation. Different MgO contents (1.5–11.25 wt %) were employed for the preparation of supports, and NiO loadings were in the range of 10–40 wt %. The optimum catalyst prepared from proper amounts of MgO (∼2 wt %) and NiO loading (20 wt %) with [Ni(en)2(H2O)2](NO3)2 as precursor and a mesoporous support with a wide range of mesopores resulted in highly dispersed nickel nanoparticles that exhibited moderate metal–support interactions, lower acidic surface sites, and enhanced performance over the entire range of operating conditions. The optimum catalyst also showed a high activity and resistance to coke formation and sintering as compared to catalysts prepared with either MgO or [Ni(en)2(H2O)2](NO3)2. Complete CO conversion could be achieved at 300 °C for this catalyst where other prepared catalysts had achieved about 60% CO conversion.