The stability of rhodium catalysts supported on gadolinium doped ceria for the steam reforming reaction is investigated. High temperature reduction of the fresh catalyst in hydrogen results in the typical symptoms of SMSI. Under steam reforming conditions, and after three subsequent reduction-reaction-oxidation cycles, the catalysts showed stable performance. Based on the results an activation procedure was developed and stable performance of over 190 h was demonstrated. (c) 2007 Elsevier B.V. All rights reserved.