Carbon dioxide reforming of methane over Ni/Mg0.4Al0.4-La0.1Zr0.1(O) catalyst prepared by recombination sol–gel method

Abstract

Based on several catalysts preparation methods, we developed a new sol–gel method and produce a series of quaternary catalysts Ni/MgxAlx-La0.5-xZr0.5-x(O) (x = 0, 0.13, 0.25, 0.33, 0.4, 0.43, 0.5) using different ratios of binary metallic oxide (MgAl(O) to LaZr(O)). The synthesized samples were employed in the dry reforming of methane (DRM) and mixed reforming of hydrocarbons (CH4 & C2H6) (MRH) to evaluate their performances at 800 °C under atmospheric pressure. The experimental result indicates that the catalytic activity was mainly dependent on the interaction between active component (NiO particle) and support, and Ni/Mg0.4Al0.4-La0.1Zr0.1(O) exhibited the highest activity (CH4 96.1% & CO2 95.9%) during DRM. The physicochemical properties of these catalysts were analyzed by N2 adsorption–desorption, X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), H2 temperature-programmed reduction (H2-TPR) and thermogravimetric analysis (TGA). The TPR analysis result illustrated that strong interaction between Ni active species and support was observed on catalysis Ni/Mg0.4Al0.4-La0.1Zr0.1(O), increasing the stability of Ni and thus enhanced both abilities of anti-sintering and anti-coking during the reaction. The XRD characterization of fresh and used Mg0.4Al0.4-La0.1Zr0.1(O) witnessed that the active component Ni was well dispersed on the support, and the minimal carbon deposition was detected on the used Ni/Mg0.4Al0.4-La0.1Zr0.1(O) by TGA and SEM compared with other catalysts. The 80 h activity test confirmed that the Mg0.4Al0.4-La0.1Zr0.1(O) can still perform high conversions (both CH4 & CO2 > 95% after 80 h) and stability after a long time DRM reaction. Moreover, the quaternary Ni/Mg0.4Al0.4-La0.1Zr0.1(O) is also suitable for mixed hydrocarbons reforming to produce syngas, which showed its excellent performance (CH4 94%, CO2 96% and C2H6 100%) during the reaction and may be widely used in the future.