MoOx-Doped Ni/3D-SBA-15 Catalyst for CO Methanation: Effect of Solvent and MoOx Promoter on the Catalytic Properties

Abstract：It is a challenge to simultaneously improve the low-temperature activity and long-lived stability of the catalyst for a high-temperature reaction. In this work, MoOx-doped Ni/3D-SBA-15 catalysts with three-dimensional network structure were prepared by an impregnation method using ethylene glycol as solvent for CO methanation reaction. In addition, H2O was used as solvent for comparison. The catalyst prepared in the presence of ethylene glycol, shows high specific surface area, small Ni particle size, and high metal dispersion. The addition of Mo promoter can further improve the Ni dispersion and decrease the interaction between NiO species and the support. After reduction at 600 oC, the Mo promoter is in the mixed-valence of MoOx (x<3), which can increase the density of Ni atomic electron clouds. As a result, the Ni-MoOx/3D-SBA-15 catalyst exhibits the highest low-temperature activity, whose CO conversion reaches 99.3 % at 320 oC, 0.1 MPa, 60000 mL g‒1 h‒1. During the 100h-lifetime test, this catalyst exhibits high stability due to the small Ni particle, appropriate metal-support interaction, the promotion of MoOx species as well as confinement effect of 3D-SBA-15 support. Keywords: CO methanation, ethylene glycol, MoOx, Ni catalyst, 3D-SBA-15