Regularities of Modification of Active Carbons by Oxygen-Containing Manganese Compounds

Resumo

Composite materials resulted from impregnation of active carbons with aqueous solutions of manganese (II) chloride were studied by the methods of gas adsorption, X-ray powder diffraction, atomic absorption spectrometry, energy-dispersive X-ray spectroscopy, and scanning electron microscopy. The texture and specific characteristics of porosity, microporosity, and composition of the prepared composites were found to change depending on the acidic or basic nature of the surface of initial carbons, conditions of impregnation, subsequent treatment, and calcination temperature. It was shown that, upon the impregnation of the “acidic” carbons, the total pore volume covered 8–11 times the micropore volume, as distinct from the “basic” samples, which showed only a two- or threefold excess. The specific BET surface determined for the “acidic” carbons exceeded the value found for the samples with a “basic” surface. It was confirmed that the prepared composites contained manganese in various manganese-oxide compounds including ramsdellite, hausmannite, manganosite, bixbyite, and partridgeite at concentrations of 23–48 wt %.