Chromium Poisoning of LSM-YSZ SOFC Cathodes I. Detailed Study of the Distribution of Chromium Species at a Porous, Single-Phase Cathode
Chromium Poisoning of LSM-YSZ SOFC Cathodes I. Detailed Study of the Distribution of Chromium Species at a Porous, Single-Phase Cathode
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DOI：
10.1149/1.1806392
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发表时间：
2004-11
影响因子：
3.9
通讯作者：
S. Paulson;V. Birss
中科院分区：
文献类型：
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作者：
S. Paulson;V. Birss
对 8 mol% 氧化钇稳定氧化锆 (YSZ) 晶片进行了详细的化学和表面结构分析，该晶片部分覆盖有薄的多孔 (La 0.8 Sr 0.2 ) 0.98 MnO 3 (LSM) 薄膜电极，在 800°C 的氧化铬源存在下发生阴极中毒后。在所使用的条件下，新沉积的含铬化合物不仅分布在电活性LSM-YSZ-空气三相边界（TPB）界面区域内和周围，而且还延伸约100nm。从 LSM 薄膜边缘到 YSZ 表面 500 μm。 YSZ 表面 Cr 物质的分布和结构与固体氧化物燃料电池 (SOFC) 半电池阴极极化的变化直接相关。考虑到电化学活性仅发生在 LSM-YSZ-air TPB 上，这种结构是没有预料到的。这里提供的证据表明，Cr 2 O 3 通过有效地创建新的 Cr 2 O 3 -YSZ-空气 TPB 区域，在将电活性 LSM-YSZ-空气 TPB 延伸到 YSZ 表面上方面发挥着重要作用。
Detailed chemical and surface structure analyses are presented for an 8 mol % yttria-stabilized zirconia (YSZ) wafer, partially covered with a thin, porous (La 0.8 Sr 0.2 ) 0.98 MnO 3 (LSM) film electrode, after being cathodically poisoned in the presence of a chromia source at 800°C. Under the conditions used, the newly deposited Cr-containing compounds were distributed not only in and around the electroactive LSM-YSZ-air triple-phase boundary (TPB) interface region, but also extending ca. 500 μm from the edge of the LSM film onto the YSZ surface. The distribution and structure of the Cr species on the YSZ surface was directly correlated with variations in the cathodic polarization of the half-cell for a solid oxide fuel cell (SOFC). Such structuring was not anticipated, considering that the electrochemical activity is thought to occur only at the LSM-YSZ-air TPB. Evidence presented here suggests that Cr 2 O 3 plays an important role in extending the electroactive LSM-YSZ-air TPB out onto the YSZ surface by effectively creating a new Cr 2 O 3 -YSZ-air TPB region.