Synthesis and Catalytic Performance of Manganese Oxide Octahedral Molecular Sieve Nanorods for Formaldehyde Oxidation at Low Temperature

Abstract

Uniform manganese oxide octahedral molecular sieve (OMS-2) nanorods were synthesized by adding a small quantity of K2S2O8 to the solution containing MnSO4·H2O and KMnO4, and used for complete oxidation of formaldehyde. According to the results of N2 adsorption and X-ray diffraction, the material is a manganese oxide octahedral molecular sieve with the cryptomelane type structure. TEM observation shows that the diameters of the nanorods range from 15 to 25 nm, and the lengths are 300–400 nm. Complete conversion of HCHO to CO2 and H2O can be achieved at 353 K over OMS-2, and the same conversion is obtained at 373 K on the MnOx powder under the same conditions, which demonstrates that the catalytic activity is closely related to the morphology of the catalysts.