The construction of the Ni/La2O2CO3 nanorods catalysts with enhanced low-temperature CO2 methanation activities

Abstract

In this work, the La(OH)3 nanorods were successfully synthesized by precisely regulating the parameters of the hydrothermal method. Then, a series of Ni-based CO2 methanation catalysts were fabricated via the incipient-wetness impregnation and deposition–precipitation methods by employing the La(OH)3 nanorods as the supports. The influences of the support morphology and the preparation method on the metal-support interaction, Ni dispersion, and the surface basicity were carefully investigated based on various techniques, such as XRD, SEM, H2-TPR, CO2-TPD, XPS, ect. It was found that the rod-shaped La(OH)3 supported catalyst prepared by the deposition–precipitation method performed the optimum activity and stability. The reason for this could be derived from the confinement effect of the crystal plane of the rod-shaped support, which would promote the formation of the strong metal-support interaction and the construction of the Ni-La interface with high activity. Furthermore, the online-tandem TG-MS and in-situ DRIFTS technologies were used to investigate the thermal decomposition performance of the catalyst precursors in the calcination process and the reaction intermediates of the CO2 methanation. Therefore, the fundamental roles of support morphology and catalyst preparation method were expected to direct the advancement of the Ni-based nanostructured catalysts with outstanding low-temperature performances.