Carbon dioxide reforming of methane over Ni nanoparticles incorporated into mesoporous amorphous ZrO2 matrix

Abstract

A series of mesoporous amorphous Ni–ZrO2 composite oxides with varying Ni contents were prepared by an improved co-precipitation/reflux digestion method and evaluated in the dry reforming of methane. The synthesis method enabled the preparation of uniformly sized Ni particles evenly dispersed within the porous amorphous zirconia matrix. The catalytic reaction results showed that mesoporous amorphous Ni–ZrO2-CR-15 catalyst (Ni loading of 15wt%) exhibited the highest catalytic activity and excellent stability during the 80-h test among other studied Ni–ZrO2 catalysts. Rapid decline in the catalytic activity was observed for catalysts prepared by traditional impregnation and co-precipitation methods. The improved catalytic performance was attributed to the homogeneous distribution of the small Ni nanoparticles because of the high surface area of the amorphous structure and the strong interaction between Ni and ZrO2. Additionally, the confinement effect of the nano-amorphous structure was responsible for the superior thermal stability of the Ni nanoparticles. Furthermore, Ni–ZrO2-CR-15 catalyst displayed high resistance against carbon deposition owing to the presence of multiple interfaces between the metal and oxide support, absence of strong Lewis acid sites, and presence of different active centers for CO2 dissociation.