New Nanocrystalline Cu/MnOx Catalysts Prepared from Supercritical Antisolvent Precipitation

Supercritical CO2 is used as an antisolvent to precipitate out nanostructured homogeneous mixtures of Cu2+ and Mn3+ with crystallites of 10-20 nm in diameter. Following calcination, this material forms a crystalline tetragonal spinel, CuMn2O4, with a branched chainlike structure with a length of 160-200 nm and diameters of approximately 40 nm. This new material is more than twice as active per unit surface area as the conventionally prepared hopcalite catalysts for the oxidation of carbon monoxide. This is the first time that homogeneous mixed oxides have been formed using this method.