From Al2O3-supported Ni(II)-ethylenediamine Complexes to CO Hydrogenation Catalysts: Importance of the Hydrogen Post-treatment Evidenced by XPS
Ni (7 wt%)/Al2O3 catalysts prepared by decomposition of Ni(II)-ethylenediamine complexes in inert atmosphere initially contain a mixture of metallic and oxidized nickel. X-ray photoelectron spectroscopy shows that after a hydrogen treatment at 500 °C, the system contains more metallic nickel than catalysts prepared from the usual precursor, nickel nitrate. Carbonaceous species resulting from the partial oxidation of ethylenediamine are also eliminated. The catalyst post-treated in hydrogen exhibits a high metallic surface area accessible to reactants and is able to catalyze CO methanation.