Preparation and Characterization of Ni-Mn/ZrO_2-CeO_2 Catalysts for Hydrogen Production via Methane Decomposition

摘要

Catalysts with different Ni contents supported on improved ZrO_2-CeO_2 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 m~2/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 Ni~0. 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.