Preparation and Characterization of a Cerium(IV)-incorporated Manganese Oxide OMS-2. Effect of Cerium(IV) Template on Octahedral Molecular Sieves of Manganese Oxide and Characterization of Manganese Oxide Molecular Sieves with Cerium(IV) as Dopant

Abstract

The manganese oxide material K-OMS-2 was synthesized both via a redox reaction between potassium permanganate and manganese nitrate in an acidic medium (nitric acid) under reflux conditions and by the sol–gel reaction between KMnO4 and maleic acid employed in a 3:1 molar ratio. Cerium(IV) was then added by an ion-exchange method. The structures, morphologies, chemical compositions and thermal stabilities of the resulting materials were studied by X-ray diffraction (XRD), N2 adsorption/desorption, scanning electron microscopy (SEM), Fourier-transform infrared (FT-IR) spectroscopy, differential scanning calorimetry (DSC) and TGA techniques. Both the morphologies and the surface properties of the materials synthesized by these two methods were different. Thus, the material prepared via the sol–gel process possessed a higher surface area and exhibited both a different type of adsorption isotherm and smaller crystallite sizes than the material synthesized by redox reaction under reflux conditions. The physical...