Dispersion–precipitation synthesis of nanorod Mn3O4 with high reducibility and the catalytic complete oxidation of air pollutants

Abstract

Manganese oxide catalyst was prepared by a novel dispersion–precipitation method, which involved synthesis of stable aqueous dispersion of manganese oxide nanoparticles and the subsequent precipitation by dilution-induced destabilization. The characterizations indicated that the thus prepared catalyst was composed of nanorod particles with a Hausmannite structure of Mn 3 O 4 , and had a high reducibility. In comparison to the catalysts prepared by alkaline-salt reaction or calcination of manganese acetate, this catalyst prepared by the new method showed much better performance in the catalytic complete oxidation of airborne carbon monoxide and toluene, which is possibly attributed to the smaller particle sizes and higher oxygen mobility. ► Dilution leads to destabilization and precipitation of manganese oxide nanoparticles in aqueous solution. ► The dispersion–precipitation process produces Mn 3 O 4 nanorods. ► Nanorod Mn 3 O 4 catalyst is highly reducible. ► Nanorod Mn 3 O 4 is effective in elimination of airborne carbon monoxide and toluene.