Synthesis and characterization of mesoporous alumina with nickel incorporated for use in the partial oxidation of methane into synthesis gas

Abstract

Mesoporous alumina catalysts that incorporate nickel (Ni-Alumina) with different Ni/Al molar ratios of 1:2, 1:5 and 1:10 were synthesized by a one-step sol–gel method using lauric acid as a template. The prepared Ni-Alumina catalysts showed a relatively high surface area with a narrow pore size distribution after calcination at 700 °C; these effects were independent of the Ni/Al molar ratio. Although weak interactions between nickel oxide and alumina were observed in the Ni-Alumina catalysts with increasing the amounts of nickel precursor, nickel catalysts finely dispersed on an alumina support were obtained in all cases. The Ni-Alumina catalysts were found to be highly active in the partial oxidation of methane. For the purposes of comparison, a nickel catalyst impregnated on a commercially available alumina support was prepared (Ni-IMP). Various characterization results showed that the 1:10 Ni-Alumina catalyst had stronger metal-support interactions and a more favorable catalyst structure for obtaining finely dispersed nickel particles, compared to the Ni-IMP catalyst. The deactivation of catalysts examined in this work was not due to catalyst sintering, but mainly to the carbon deposition. The Ni-Alumina catalyst having smaller nickel particles and lower levels of carbon deposition had a more stable catalytic activity than the Ni-IMP catalyst.