Surface condition, manganese dioxide

This paper deals with preparation and characterization of frame structured cordierite-like honeycomb catalysts modified with manganese dioxide that is active in high-temperature NH3 oxidation to NO. We study the effect of 3d-cation addition on the formation of cordierite stmcture, texture, surface morphology and activity of modified cordierites in ammonia oxidation reaction. The effect of preparation condition (type and duration of mechanical treatment, calcination temperature) was studied as well. 

This study focused on the deactivation of the Mn/Ce catalysts during reaction. The catalytic oxidation of phenol in aqueous solution to carbon dioxide, water and other side-products was selected as the test reaction. Catalysts were prepared from amorphous precursors using the citrate method and controlling the calcination temperature. Activity performance as a function of the time on stream was studied by simultaneously analyzing the conversion of phenol, the total organic carbon content of the catiyst, the cations eluted and the elemental composition of both cerium and manganese. Experimental conditions were widely varied. Fresh and used catalysts were also analyzed by BET surface area, X-Ray Diffraction and X-Ray Photoelectron Spectroscopy. 

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