A series of cobalt-based monolithic catalysts supported on mixture of YSZ-γ-Al₂O₃ and CeO₂-Y₂O₃-ZrO₂ were prepared by impregnation method, and characterized by XRD, XPS, BET and H₂-TPR. Contrasting with the 8 wt% Co₃O₄-based monolithic catalyst supported on YSZ-γ-Al₂O₃ or CeO₂-Y₂O₃-ZrO₂, the catalytic activities for methane combustion were assessed in a micro-reactor. All the mixture supported monolithic catalysts had higher activity for methane combustion than the contrast catalysts. After calcination at 1000 ℃ for 5 h, the monolithic catalysts remained highly active and very stable, especially the catalyst containing 8 wt% of Co₃O₄ had the highest activity and methane was completely converted to CO₂ at ca. 514 ℃. The results showed that the mixture had the advantage of CeO₂-Y₂O₃-ZrO₂ and YSZ-γ-Al₂O₃ (γ-Al₂O₃ modified by Y₂O₃ and ZrO₂) and can resist forming the crystal of CoAl₂O₄ effectively.

Key words: methane catalytic combustion, monolithic catalyst, Co₃O₄, YSZ-γ-Al₂O₃, CeO₂-Y₂O₃-ZrO₂