Effect of the Composition of an Oxide Coating and the Preparation Method of Block Catalysts on Their Activity in the Deep Oxidation of Methane

摘要

Deep methane oxidation catalysts containing 3d metal (Mn, Co), rare-earth (La) and alkali-earth (Ba, Sr) oxides in the porous matrices of secondary supports (Al_2O_3, ZrO_2, and their binary composition) formed on honeycomb blocks (cordierite, kaolin-aerosil) are studied by means of X-ray powder diffraction, the thermal desorption of nitrogen, and temperature-programmed reduction with hydrogen. It is shown that the activity and stability of the catalysts depend on the method for their preparation and the nature of the active components and secondary and block supports. After life cycle tests, the proposed catalysts with 80– 100% conversion of methane into CO_2 at temperatures of 650–750°C can be recommended for use in sys- tems for the catalytic purification of gases containing hydrocarbon admixtures (methane and C_2–C_4 homo- logues) and the combustion of hydrocarbon fuels in industrial and household catalytic heat generators.