Dense mixed proton and electron conducting membrane made of BaCe0.95Nd0.05O3-δ （BCNd5） was prepared by pressing followed by sintering. X-ray diffraction （XRD） was used to characterize the phase structure of both the powder and the sintered membranes. The microstructure of the sintered membranes was studied by scanning electron microscopy （SEM）. Hydrogen permeation through the BCNd5 membrane was studied using a high temperature permeator. The hydrogen permeation fluxes under wet conditions are higher than those under dry conditions, which is due to H^＋ hopping via surface OH groups. At 925℃, a hydrogen permeation flux of 0.02 mL/min cm^2 was obtained under wet condition, which recommends BCNd5 as a potential material for hydrogen-selective membranes.
Ming Ya CaiHui Xia LuoZhong LiArmin FeldhoffJtirgen CaroHai Hui Wang
A novel cobalt-free perovskite based on Ba0.5Sr0.5Fe0.8Zn0.2O3-δ （BSFZ） were prepared by EDTA-citric acid method. The lattice constants of the BSFZ perovskite were characterized by in situ high-temperature X-ray diffraction （HTXRD）. The thermal expansion coefficient of BSFZ is 10.5×10^-6 K^-1, which is lower than that of cobalt-based perovskite materials. The BSFZ membrane was also used to construct reactors for the partial oxidation of methane （POM） to syngas. Results show that the BSFZ membrane can be operated for the POM reaction for more than 100 h without any fractures. The CO selectivity of 97% is obtained. The steady oxygen permeation flux reaches around 2.5 mL/min cm^2 during POM reaction.
Hui Xia LuoLing Hui YuXin Zhi ChenHai Hui WangJtirgen Caro
