A core-shell structured, metal-ceramic composite-supported Ru catalyst for methane steam reforming

Methane steam reforming on a metal-ceramic composite-supported ruthenium catalyst is studied at high temperatures. The core-shell structured Al ₂O ₃@Al composite consisting primarily of an Al metal core with a high surface area γ-Al ₂O ₃ overlayer is obtained by hydrothermal oxidation. Under the synthesis condition, primary Al ₂O ₃@Al particles aggregate to form a hierarchal secondary structure with macrosize inter-pores. This core-shell composite support enhances the heat conductivity and provides a high surface area for fine dispersion of a catalytic Ru component on the γ-Al ₂O ₃ overlayer. The Ru/Al ₂O ₃@Al catalyst exhibits significantly higher CH ₄ conversion than the conventional Ru/Al ₂O ₃ catalyst, indicating its superior properties for methane steam reforming at high temperatures contributed due to the fine Ru dispersion and facilitated heat and mass transfer via the unique catalyst structure. This metal-ceramic composite catalyst is stable in the reforming reaction for an extended time, suggesting reasonable stability in its physicochemical properties.