Ni-Based catalysts supported on natural clay of attapulgite applied in the dry reforming of methane reaction

Abstract

With the increase of the global average temperature year after year, dry reforming of methane to synthetic gas as a way to deal with reaction between greenhouse gases CO₂ and CH₄, therefore, has become a research focus. In this work, using an impregnation method, nickel nitrate was loaded onto attapulgite (ATP) support, which is a low-cost natural mineral material, followed by coating with Ce, Mn and Mg oxide shell. After calcining treatment, Ni–ATP@M (M = Ce, Mg, Mn) sandwich-like structure catalysts were successfully prepared. Compared with Ni/ATP, the sandwich-like structure catalysts showed better conversion rate and stability. Interestingly, the Ce and Mg oxide-modified catalysts affected the surface area with strong interaction and catalyst basicity leading to the improvement of catalyst performance. MnO can increase the electron cloud densities of Ni and the rate of hydrogen spill-over and accelerate C–O dissociation. Among the three catalysts, Ni–ATP@Ce afforded the highest conversion of CH₄ (58%) and CO₂ (74%) at a reaction temperature of 700 °C and a ratio of methane to carbon dioxide of 1 : 1, mainly attributed to highest amount of oxygen vacancies and Ni⁰ on the catalyst surface.