浸渍LaNi_(0.6)Fe_(0.4)O_(3-δ)纳米颗粒对Zr_(0.84)Y_(0.16)O_(2-δ)-La_(0.8)Sr_(0.2)Cr_(0.5)Fe_(0.5)O_(3-δ)透氧膜性能的影响

Influence of Impregnated Nano-scale LaNi_(0.6)Fe_(0.4)O_(3–δ) Particles on the Oxygen Permeation Performance of Zr_(0.84)Y_(0.16)O_(2–δ)-La_(0.8)Sr_(0.2)Cr_(0.5)Fe_(0.5)O_(3–δ) Composite Membranes

采用流延–共压–共烧结法制备了具有多孔|致密|多孔Zr_(0.84)Y_(0.16)O_(2–δ)-La_(0.8)Sr_(0.2)Cr_(0.5)Fe_(0.5)O_(3–δ)(YSZ-LSCF)结构的透氧膜和多孔YSZ-LSCF|致密YSZ-LSCF|致密YSZ|致密YSZ-LSCF|多孔YSZ-LSCF结构的固体氧化物燃料电池。采用浸渍法在多孔层内壁上沉积了具有高催化活性的LaNi_(0.6)Fe_(0.4)O_(3–δ)(LNF)纳米颗粒,随着LNF浸渍量的提高,会在多孔层内壁上形成连续的导电网格,增加电化学反应活性位点,进而显著改善电极性能。当LNF浸渍量为12wt%时,电极性能达到最优,在800℃时阴极和阳极极化阻抗分别为0.26和0.08?·cm^2,在空气/CH_4梯度中氧渗透速率为7.6 mL/(cm^2·min),比未浸渍前提高了14倍。阻抗谱分析表明空气侧氧还原反应中的电荷转移反应是氧渗透过程的速率控制步骤。

This paper reported on the fabrication of tri-layered oxygen transport membranes, “porous｜dense｜porous” Zr0.84Y0.16O2-δ-La0.8Sr0.2Cr0.5Fe0.5O3-δ （YSZ-LSCF）, by the tape casting, tape lamination and co-firing techniques. Catalytically active nano-scale particles of LaNi0.6Fe0.4O3-δ （LNF） were impregnated into the porous scaffolds. In order to quantatively determine the resistances of the oxygen reduction or evolution reactions against oxygen permeation, an additional dense YSZ layer was introduced inside the dense YSZ-LSCF permeation layer. Electrochemical measurements on the resulting five-layered solid oxide fuel cells showed a large reduction in the interfacial polarization resistances at the presence of these LNF catalysts, with the lowest values observed at the LNF loadings of 12wt%. In particular, the cathodic and anodic polarization resistances were 0.26 and 0.08 Ω·cm2 at 800℃, respectively. The oxygen permeation flux under the air/CH4 gradient was 7.6 mL/（cm2·min）, which was 14 times higher than the measured value for the blank YSZ-LSCF membrane. Further impedance analysis indicated that the charge transfer step during oxygen reduction may limit the overall oxygen permeation process.