High oxygen permeation flux of cobalt-free Cu-based ceramic dual-phase membranes

Here we report a new group of cobalt-free Cu-based dual-phase oxygen permeation membranes made up of Ce0.85Pr0.1Cu0.05O2-δ and PrxSr1-xFe1-yCuyO3-δ (x = 0.4, 0.6, y = 0.05, 0.1, 0.2). The structure, oxygen permeability and stability investigations are presented. Systematic studies reveal that the synergism of these two copper-based mixed ionic-electronic conducting (MIEC) oxides can reduce the sintering temperature and give rise to attractive oxygen permeability. We find the optimal 60 wt%Ce0.85Pr0.1Cu0.05O2-δ-40 wt%Pr0.4Sr0.6Fe0.95Cu0.05O3-δ composite displays the largest oxygen permeation flux with 1.60 mL min−1·cm−2 at 1000 °C under air/He gradient and retain a steady oxygen permeation flux for over 105 h. Moreover, the 60 wt%Ce0.85Pr0.1Cu0.05O2-δ-40 wt%Pr0.4Sr0.6Fe0.95Cu0.05O3-δ membrane yields an oxygen permeation flux of 0.98 mL min−1·cm−2 at 1000 °C under air/CO2 gradient and hold the close value over 65 h. Our findings are expected to promote further studies on new oxygen permeable composites and boost the possible applications in CO2 capture.