Synthesis, Characterization, and Ion-Exchange Properties of Zinc and Magnesium Manganese Oxides Confined within MCM-41 Channels

Abstract

Zinc− and magnesium−manganese oxide particles have been grown in the pores of MCM-41 using a procedure adapted from a mild synthesis for layered manganese oxides. The Mn-modified silicates were analyzed by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS), N 2 sorption, infrared (IR) spectroscopy, diffuse reflectance ultraviolet−visible (DRUV−vis) spectroscopy, electron spin resonance (ESR) spectroscopy, X-ray photoelectron spectroscopy (XPS), and thermogravimetric analysis (TGA), and the ion-exchange and electrochemical properties were tested. The occluded manganese oxide consisted of well-dispersed, multivalent particles with a weakly ordered or amorphous structure. Ion-exchange studies determined that the occluded manganese oxide was more accessible to exchanging ions than bulk-layered manganese oxides prepared by a similar synthesis.