W-doped ordered mesoporous Ni–Al2O3 catalyst for methanation of carbon monoxide

Abstract

In order to simultaneously inhibit the Ni sintering and coke formation as well as investigate the effects of WO3 promoter on catalytic performance, the ordered mesoporous Ni–WO3/Al2O3 catalysts were synthesized by a facile one-pot evaporation-induced self-assembly method for CO methanation reaction to produce synthetic natural gas. Addition of WO3 species could significantly promote the catalytic activity due to the enhancement of the Ni reducibility and the increase of active centers, and the optimal N10W5/OMA catalyst with NiO of 10 wt% and WO3 of 5 wt% achieved the maximum CH4 yield 80% at 425 °C, 0.1 MPa and a weight hourly space velocity of 60000 mL g−1 h−1. Besides, the reference catalyst N10W5/OMA-Im prepared by the conventional co-impregnation method was also evaluated. Compared with N10W5/OMA, N10W5/OMA-Im showed lower catalytic activity due to the partial block of channels by Ni and WO3 nanoparticles, which reduced active centers and restrict the mass transfer during the reaction. In addition, the N10W5/OMA catalyst showed superior anti-sintering and anti-coking properties in a 425oC-100 h-lifetime test, mainly because of confinement effect of ordered mesoporous structure to anchor the Ni particle in the alumina matrix.