Ni nanoparticles highly dispersed on ZrO2 and modified with La2O3 for CO methanation

Abstract

To improve the anti-sintering and anti-carbon deposition ability of the supported metallic nano catalysts, a new scheme for designing and preparing catalysts for CO methanation is presented in this work. In the scheme, a series of xLaNiO₃/ZrO₂ (x = 15%, 20%, 25%) catalysts were prepared according to the citrate complexing method. The catalysts were characterized by using BET, XRD, H₂-chemisorption, H₂-TPR, and TEM technologies. After reduction, the LaNiO₃/ZrO₂ catalyst precursor preferred to form Ni nanoparticles highly dispersed on ZrO₂ and modified with La₂O₃. Compared with the catalyst prepared by the traditional impregnation method, the Ni/La₂O₃–ZrO₂ derived from LaNiO₃/ZrO₂ showed a higher dispersion of Ni on ZrO₂ and exhibited higher CO conversion and CH₄ selectivity. Meanwhile, the LaNiO₃/ZrO₂ catalyst showed excellent stability owing to the significant improvement in both anti-carbon deposition and anti-sintering. The catalyst prepared according to this scheme intensified the interaction between Ni and La₂O₃, thus favoring the synergistic effect of La₂O₃ and Ni, which led to the high dispersion of Ni nanoparticles as well as the very good anti-sintering and anti-carbon deposition ability.