Abstract Thanks to its high hydrogen permeability and good chemical stability in moist CO 2 environments, BaCe 0.65 Zr 0.20 Y 0.15 O 3-δ -Ce 0.85 Gd 0.15 O 2-δ mixed conducting material is considered one of the most promising candidates for hydrogen separation ceramic membranes. In this work, its chemical stability under H 2 S-rich atmosphere was systematically investigated by in-situ electrochemical characterizations and ex-situ structural, chemical and morphological analyses. A performance degradation of the total conductivity depending on the H 2 S content was observed: at 700 °C and under 1500 and 700 ppm of H 2 S the conductivity drop was 15% and 2% respectively. The complementary information gathered by morphological and chemical analyses showed that the changes responsible for the total conductivity degradation are mainly confined to the surface of the membrane. Indeed, after the exposure to the H 2 S-containing atmosphere, some traces of sulfur-related compounds were detected only on the top of the membrane while the bulk preserved a fully dense structure with well-defined grain boundaries and no evidence of cracks. However, no evidence of S-based compounds were revealed by structural investigations, probably due to the detection limit of these techniques and/or to the low crystallinity of the secondary phases. Contrary to Pd-based membranes that are severely deteriorated by a few ppm of sulfur, this material shows an acceptable stability even under 700 ppm of H 2 S and could be attractive for tailored applications such as, for example, operations related to steam reforming of methane often containing 10–300 ppm of H 2 S.

中文翻译：

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用于氢分离膜的 BaCe 0.65 Zr 0.20 Y 0.15 O 3-δ -Ce 0.85 Gd 0.15 O 2-δ 复合材料的硫耐受性增强

摘要 BaCe 0.65 Zr 0.20 Y 0.15 O 3-δ -Ce 0.85 Gd 0.15 O 2-δ 混合导电材料由于其在潮湿CO 2 环境中的高透氢性和良好的化学稳定性，被认为是最有前途的氢分离候选材料之一。陶瓷膜。在这项工作中，通过原位电化学表征和异位结构、化学和形态分析系统地研究了其在富含 H 2 S 的气氛下的化学稳定性。观察到取决于 H 2 S 含量的总电导率的性能下降：在 700 °C 和低于 1500 和 700 ppm H 2 S 时，电导率下降分别为 15% 和 2%。通过形态学和化学分析收集的补充信息表明，导致总电导率下降的变化主要局限于膜表面。事实上，在暴露于含 H 2 S 的气氛后，仅在膜的顶部检测到一些痕量的硫相关化合物，而主体保持完全致密的结构，具有明确的晶界且没有裂纹的迹象。然而，结构研究没有发现 S 基化合物的证据，这可能是由于这些技术的检测极限和/或第二相的低结晶度。与被几 ppm 硫严重损坏的 Pd 基膜相反，