Using oxygen permeable membranes (OPMs) to upgrade low-purity hydrogen is a promising concept for highpurity H 2 production. At high temperatures, water dissociates into hydrogen and oxygen. The oxygen permeates through OPM and oxidizes hydrogen in a waste stream on the other side of the membrane. Pure hydrogen can be obtained on the water-splitting side after condensation. However, the existing Co-and Fe-based OPMs are chemically instable as a result of the over-reduction of Co and Fe ions under reducing atmospheres. Herein, a dual-phase membrane Ce 0.9 Pr 0.1 O 2Àd-Pr 0.1 Sr 0.9 Mg 0.1 Ti 0.9 O 3Àd (CPO-PSM-Ti) with excellent chemical stability and mixed oxygen ionic-electronic conductivity under reducing atmospheres was developed for H 2 purification. An acceptable H 2 production rate of 0.52 mL min À1 cm À2 is achieved at 940 8C. No obvious degradation during 180 h of operation indicates the robust stability of CPO-PSM-Ti membrane. The proven mixed conductivity and excellent stability of CPO-PSM-Ti give prospective advantages over existing OPMs for upgrading low-purity hydrogen.