采用固相反应法成功制备了(La1－x Ndx )5．5 WO12－δ(x＝1/3,1/2)质子-电子混合导体.运用 X射线衍射仪(XRD)、扫描电子显微镜(SEM)分别对试样的物相结构、微观形貌进行了表征.测试了试样在湿润CO2气氛中的化学稳定性,应用交流阻抗法测定了其在空气和湿润5％ H 2/Ar 气氛中的电导率,并研究了试样在不同温度、不同氢分压下的透氢量.结果表明,(La1－xNdx)5．5 WO12－δ(x＝1/3,1/2)经1550℃烧结后均形成立方萤石结构的致密烧结体；试样在800℃湿润CO2气氛中均表现出良好的化学稳定性；试样在湿润5％ H 2/Ar 气氛下的电导率明显高于空气气氛,在湿润5％ H2/Ar 气氛中850℃时,(La1/2 Nd1/2)5．5 WO12－δ的电导率达到6．58×10－3 S/cm；在900℃、50％ H2/N2时,厚度为1．56 mm 的(La1/2 Nd1/2)5．5 WO12－δ透氢膜获得最大透氢量为0．079 mL/(min?cm2).
Mixed proton-electron conductors of (La1-xNdx)5.5 WO12-δ(x=1/3,1/2)were successfully synthe-sized by the solid state reaction route.The phase composition and microstructures of the samples were investiga-ted by XRD and SEM,respectively.Chemical stability against humid CO2 was tested.The total conductivities of the samples in air and wet 5% H2/Ar atmospheres were measured by the AC impedance spectroscopy.Hydro-gen permeation performance of the membranes was tested at different temperatures and hydrogen partial pres-sures.The results indicate that the samples sintered at 1 550 ℃ were cubic fluorite structure and the samples were extremely dense.The samples are quite stable in humid CO2 atmosphere.The samples have higher conduc-tivities in wet 5% H2/Ar and (La1/2 Nd1/2 )5.5 WO12-δpresents a high conductivity in wet 5% H2/Ar,which was about 6.58×10-3 S/cm at 850 ℃.Using 50% H2/N2 as feed gas,the highest hydrogen flux for (La1/2 Nd1/2 )5.5 WO12-δmembrane with thickness of 1.56 mm was 0.079 mL/(min??cm2)at 900 ℃.
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