The interaction of H with a composite Pt/Ce0.6Zr0.4O2/Al2O3 system and its redox properties are investigated by means of H-2 and O-2 chemisorption, temperature programmed reduction (TPR) and desorption techniques. It is shown that the high H-2 spillover capabilities of Pt/CeO2-ZrO2 are maintained even after supporting the system on Al2O3. The re-oxidation experiments performed on the reduced moieties show that the stability of Ce(III) species is increased by Al2O3, while the presence of Pt favours the re-oxidation. (C) 2003 Elsevier Science B.V All rights reserved.