燃料中水蒸气对(Ba0.2Sr0.8)0.9Ni0.07Fe0.63Mo0.3O3-δ钙钛矿阳极材料结构和性能的影响

Influence of water vapor in fuels on structure and performance of (Ba0.2Sr0.8)0.9Ni0.07Fe0.63Mo0.3O3-δ perovskite ceramic anode

摘要:

原位溶出技术在制备固体氧化物燃料电池（SOFC）阳极纳米催化剂具有十分广阔的前景，同时也吸引了很多研究者的注意．在800 ℃和氢气气氛下还原 (Ba0.2Sr0.8)0.9Ni0.07Fe0.63Mo0.3O3-δ（BSNFM）制备出NiFe合金纳米颗粒均匀包覆陶瓷阳极的SOFC阳极材料，同时研究了材料在不同湿氢和干氢气氛下材料的结构、形貌及电化学性能．结果表明：在800 ℃干燥氢气气氛下阳极材料转变为K2NiF4结构，而在相同温度湿润氢气氛下结构没有明显变化；虽然（Ba0.2Sr0.8）0.9Ni0.07Fe0.63Mo0.3O3-δ阳极材料在干氢气氛下的电导率较低、极化阻抗较大、单电池的总阻抗也较大，然而在干氢气氛下却表现出了比湿润氢气气氛下更优异的电化学性能，如在干氢气氛下800，750和700 ℃时的功率密度分别达到了904，683和450 mW/cm2，而在湿氢气氛下相应的的输出分别为832，620和413 mW/cm2，在不同气氛下均表现出了极好的稳定性．

Abstract:

In-situ exsolved nanoparticles on the surface of the solid oxide fuel cell (SOFC) anode materials have attracted extensive attentions. Herein, (Ba0.2Sr0.8)0.9Ni0.07Fe0.63Mo0.3O3-δ (BSNFM) has been reduced in H2 at 800 ℃ and utilized as SOFC anode materials. It is found that structure of the BSNFM anode was transform from ABO3 to K2NiF4 (A2BO4) in dry H2, while it kept ABO3 cubic perovskite structure in wet H2 (3 vol% H2O). After reduction, the in-situ exsolved NiFe alloy (NFA) nanoparticles were evenly decorated on the anode substrate in two samples. Interestingly, the electronic conductivity of the sample reduced in dry H2 was lower than that of the sample reduced in wet H2. While, electrochemical performance of the single cell with BSNFM anode reduced in dry H2 was better than that of the single cell with BSNFM anode reduced in wet H2. The power density of the single cell with BSNFM anode reduced in dry H2 is 904, 683, 450Mw/cm2 at 800, 750 and 700 ℃, while that of the single cell with BSNFM anode reduced in wet H2 is 832, 620, 413mW cm-2 in wet hydrogen at 800, 750 and 700 ℃.