Reinforcement of steam oxidative cracking of 1-methyl naphthalene by the synergistic combination of hydrogenation and oxidation over nickel-containing mixed oxide catalysts.

Graphical abstract Highlights • Ni-containing mixed oxide catalysts were employed for steam oxidative cracking. • Strong metal-support interactions increased Ni metallic and oxygen vacant sites. • Ni-containing catalysts preferred steam oxidative cracking route to steam reforming. • Steam oxidative cracking was enhanced by combination of hydrogenation and oxidation. • Enhancement of steam oxidative cracking resulted in high liquid yield in the process. Abstract Steam oxidative cracking route of 1-methyl naphthalene were investigated through the combination of oxidation and hydrogenation over nickel-containing mixed oxide catalysts. Depending on the used supports, several types of active sites for oxidation, hydrogenation, and steam decomposition were generated by various metal–support and support–support interactions. The steam reforming routes were dominant without nickel, resulting in high carbon selectivity of gas due to a full-cracking process. With nickel, steam oxidative cracking routes were strongly enhanced by a synergistic combination between hydrogenation occurring on the Ni metallic sites and oxidation over mobile lattice oxygens in a Ce x Zr 1-x O 2 solid solution, resulting to the higher carbon selectivity of liquid products than that of gas products. Among the prepared catalysts, optimal interaction between Ni and ceria-zirconia-alumina mixed oxide support caused not only an increase of oxygen vacancies in solid solutions, but also the formation of smaller Ni metallic nanoparticles, resulting in reinforcement of steam oxidative cracking of 1-methylnaphthanlene. [ABSTRACT FROM AUTHOR]