The prospects of using mixed ionic/electronic conducting ceramics for syngas production in a catalytic membrane reactor are analysed. Problems relating to limited thermodynamic stability and poor dimensional stability of candidate materials are addressed, The consequences for these problems, of flux improving measures like minimization of membrane thickness and minimization of the losses due to oxygen exchange over the membrane surfaces, are discussed. The analysis is conducted on two candidate materials: La0.6Sr0.4Co0.2Fe0.8O3-delta and SrFeCo0.5Ox. Finally. experimental investigations of the dimensional stability of the latter material under reducing conditions are reported. (C) 2000 Elsevier Science B.V. All rights reserved.