The catalytic performance of the composite catalysts of CuFe(2)O(4) spinel and various zeolites for steam reforming and hydrolysis of dimethyl ether (DME SR and DME HYD) was investigated. The catalytic activity for DME SR and DME HYD was affected by the type of zeolites and the durability of the CuFe(2)O(4) spinel catalysts composed of various zeolites was lower than those composed of alumina as solid acids. Based on several characterizations, the difference of types of zeolite led to the formation of various carbonaceous species on the catalysts during DME SR and DME HYD. The deactivation due to the coke formation was suppressed by the pre-heat treatments in air as a result of the decreasing acid strength. This high durability with heat treatment was obvious for the composite catalyst of CuFe(2)O(4) and ZSM-5 (MFI) type zeolite in DME SR. In contrast, the heat treatment did not enhance the durability of the ferrierite (FER) type zeolite composite catalyst. (C) 2010 Professor T. Nejat Veziroglu. Published by Elsevier Ltd. All rights reserved.