The influence of heat treatment on catalytic activity and durability for steam reforming of dimethyl ether (DME SR) over the composite catalysts of CuFe2O4 spinel and gamma-Al2O3 was investigated. The heat treatment in air after mixing of CuFe2O4 and Al2O3 improved the activity and durability of the composite catalysts for DME SR. The treatment temperature range of 700-800 degrees C is most effective to enhance the catalytic performance. According to XRD and TPR analyses, the new phase of Cu-Fe-AlO4 Was produced by solid-state reaction at the interface between CuFe2O4 and Al2O3 after heat treatment, leading to high catalytic performance. This new active phase also formed over the composites of pre-reduced CuFe2O4 and Al2O3, due to the re-construction of Cu-Fe spinel by the heat treatment. (C) 2009 Elsevier B.V. All rights reserved.