Preparation and characterization of Ni-Mn/ZrO₂-CeO₂ catalysts for hydrogen production via methane decomposition

Catalysts with different Ni contents supported on improved ZrO ₂-CeO₂ mixed oxides and doped with manganese as a promoter of activity were evaluated on the catalytic methane decomposition (CMD) at 500°C for hydrogen and carbon nanostructures production. The supports were synthesized by surfactant-assisted coprecipitation, and Ni and Mn deposition was performed by conventional impregnation. The surface areas for 15N1MZC and 45N1MZC solids prepared with surfactant were 13 and 28 m²/g respectively and it was observed that by incorporating 1% of Mn to the active phase the methane conversion increases. The temperature programmed reduction results indicated that the addition of Mn allows the formation of different NiO_x species, increasing the reduction degree to Ni0. The transmission electron microscopy analysis show the formation of different species of carbon as nanotubes, whiskers and onions, as well as an important number of encapsulated Ni particles.