A位缺陷对(Pr0.5Sr0.5)1-xFe0.9Ru0.1O3-δ（0≤x≤0.2）阳极材料电化学性能及稳定性影响的研究

Effects of A-site deficiency on electrochemical performance and stability of (Pr0.5Sr0.5)1-xFe0.9Ru0.1O3-δ（0≤x≤0.2） anode material

摘要:

通过燃烧法制备了不同A缺位的（Pr0.5Sr0.5）1-xFe0.9Ru0.1O3-δ（PSFRx，x=0，0.1，0.2）钙钛矿氧化物，并将其用作固体氧化燃料电池（Solid Oxide Fuel Cell, SOFC）的阳极材料，研究其在还原气氛中的析出及材料结构演变机理，探索其电化学性能及运行稳定性．实验结果表明，在经过在800 ?C还原2 h后，所有PSFRx样品的主要相结构都由ABO3立方钙钛矿相转化为Ruddlesden-Popper（RP）层状钙钛矿相，同时在表面析出Fe-Ru合金纳米颗粒．XRD结果表明，少量的A缺位（x=0.1）可以抑制在还原过程中的杂相生成，保证了B位金属析出后A2BO4层状相的稳定性．随后，对SOFC进行的电化学性能测试，随着A缺位的增加，PSFRx的电化学输出性能随之先上升后下降，A缺位的最佳缺位比例为x=0.1．在800 ?C下，以PSFR0.1为阳极的电解质支撑单电池在加湿H2和C3H8的最大功率密度分别为0.747和0.528 W?cm2．进一步，在以C3H8为燃料气、恒电流为0.15 A/cm2条件下对PSFR0.1为阳极的单电池进行放电测试，实现了稳定的功率输出．

Abstract:

The (Pr0.5Sr0.5)1-xFe0.9Ru0.1O3-δ (PSFRx，x=0，0.1，0.2) perovskite oxides with different A-sites deficiency were prepared by combustion method and used as solid oxide fuel cell (Solid Oxide Fuel Cell, SOFC) anode materials. Experimental results show that, when reduced at 800?C for 2 h, the main phase structure of all PSFRx samples was transformed from ABO3 cubic perovskite phase to Ruddlesden?Popper (RP) layered perovskite phase with Fe-Ru alloy nanoparticles precipitated on the surface. XRD results show that a small amount of A-site deficiency (x=0.1) can inhibit the generation of heterogeneous phases and guarantee the stability of the A2BO4 layered phase during the reduction process. Electrochemical performance tests of the single cells show that PSFRx electrochemical output performance rises first and then decreases with the increase of A-site deficiency content. The optimum content ratio of A-site deficiency is x=0.1. The maximum power density of single cell supported by electrolyte with PSFR0.1 anode at 800 ?C in humidification H2 and C3H8 is 0.747 and 0.528, respectively. Furthermore, the single cell shows a stability outputs at a constant current load of 0.15 A/cm2 in wet C3H8 fuels.