Comparison between unsupported mesoporous Co3O4 and supported Co3O4 on mesoporous silica as catalysts for N2O decomposition

Mesoporous Co₃O₄ (meso-Co₃O₄) and Co₃O₄ nanoparticles supported on mesoporous silica SBA-15 (Co/SBA-15) were prepared by hydrothermal synthesis and an impregnation method, respectively. Although the as-prepared meso-Co₃O₄ had mesopores and a higher surface area comparable to that of Co/SBA-15, its catalytic activity for N₂O decomposition was much lower than that of Co₃O₄/SBA-15. The low catalytic activity of meso-Co₃O₄ mainly stems from the drastic decrease of the meso-Co₃O₄ surface area under the reaction condition used. On the other hand, Co/SBA-15 maintained its high surface area and mesopores with the aid of a robust silica support. This finding indicates that Co₃O₄ supported by a support is much more stable and efficient than meso-Co₃O₄ under N₂O decomposition reaction conditions.