CO2-stable Ce0.9Gd0.1O2-δ-perovskite dual phase oxygen separation membranes and the application in partial oxidation of methane to syngas

To improve the chemical stability of perovskite materials (alkaline earth metal containing) in CO2-containing atmosphere, based on the dual phase structure membranes, we prepared three CO2-stable CGO (Ce0.9Gd0.1O2 (delta))-perovskite dual phase membranes, which takes the perovskite oxides as the electrons conducting phase and the fluorite CGO oxide (possesses inherently high chemical stability against CO2) as the oxygen ionic conductor. During the oxygen separation tests, all the membranes exhibit good reversibility when periodically changing the sweep gases from CO2 to Helium and good long-term stability in CO2, which demonstrate these CGO-perovskite dual phase membranes possess universal stability in CO2. Then one of these dual phase membranes (Ce0.9Gd0.1O2 (delta)-Ba0.5Sr0.5Co0.8Fe0.2O3 delta (CGO-BSCF)) was chosen as a model material to be applied in partial oxidation of methane (POM) to syngas. At 900 degrees C, the oxygen permeation flux of 14 mL/min cm(2), CH4 conversion of 96% and CO selectivity of 97%, and the H-2/CO of 2 were achieved. And no performance degradation of the membrane reactor was observed during continuously 230 h operation by using pure CH4 for POM at 900 degrees C. Due to the good CO2 stability and good performance in POM, the CGO-perovskite dual phase membranes could potentially stimulate their applications in industrial applications. (C) 2017 Elsevier B.V. All rights reserved.