Preparation and characterization of a higher cobalt oxide

The present paper describes the synthesis of a higher cobalt oxide system obtained from a solution technique. Low-temperature cobalt oxide system has been prepared by the reaction of sodium hydroxide and NaOCl with a cobalt nitrate aqueous solution. The composition of solid phase obtained under certain conditions is investigated by X-ray, IR, XPS- and atomic absorption spectral analyses, magnetic measurements and chemical analysis. The results obtained show that a Co oxide system may be achieved, in which Co ions are mainly in the highest oxidation state (+ 4) and in octahedral coordination. The proposed method leads to the obtaining of highly active low-temperature catalysts for oxidation of toxic substances (phenols, alcohols, aldehydes, CN- and S2-) in an aqueous medium in the absence of gaseous phase oxygen. (C) 1999 Elsevier Science S.A. All rights reserved.