Ordered mesoporous Ni/La2O3 catalysts with interfacial synergism towards CO2 activation in dry reforming of methane

Abstract

This paper describes the synthesis of ordered mesoporous Ni/La2O3 catalysts (denoted as Ni/La2O3-m) for dry reforming of methane and investigates the synergistic effect of Ni/La2O3 interfaces on the activation of CO2. The resultant nanostructured La2O3 possessed high specific surface area of 211.5 m2/g, and Ni/La2O3-m catalysts maintained the initial morphology upon thermal treatment. The mesostructure was beneficial to obtain and maintain Ni nanoparticles with sizes between 4–6 nm. Ni/La2O3-m catalysts exhibited superior activity and stability in dry reforming of methane, showing excellent performance in activating both CH4 and CO2 due to more catalytically active Ni sites and increased interfaces. In situ DRIFTS indicated that bidentate carbonate participates in coke elimination. Combined with CO2-TPD and density functional theory (DFT) calculations, we found that Ni/La2O3-m catalyst has stronger capability to promote the formation of bidentate carbonate due to the increased interfaces by enhancing Ni dispersion, which leads to better stability by suppressing the coke deposition.