Oxygen storage capacity of CuMO2 (M = Al, Fe, Mn, Ga) with a delafossite-type structure

Delafossite-type CuMO2 (M: trivalent cation) compounds were synthesized and found to exhibit oxygen storage capacity under oxidation/reduction cycle. The oxygen storage capacity values of CuFeO2 and CuMnO2 at lower temperature were larger than those of CuAlO2, CuGaO2- and CeO2-based materials. The large OSC includes an oxygen uptake at low temperature attributed to formation of metallic Cu by decomposition of the delafossite phase for CuFeO2 and CuMnO2- In the case of CuAlO2, which remained without decomposition below 800 degrees C, the oxygen uptake increased with temperature up to 0.13 mol-O/mol-CuMO2. The stability of the delafossite-type CuMO2 against oxidation/reduction cycle is affected by M3+. In this study, it was found that the oxygen storage behavior Of CuMO2 can be controlled by a combination of Cu and M ions. (C) 2008 Elsevier B.V. All rights reserved.