Pd-YSZ cermet membranes with self-repairing capability in extreme H₂S conditions

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• 作者：Sang-Yun Jeon^a ; ^b ; Bhupendra Singh^c ; Ha-Ni Im^a ; Kang-Taek Lee^d ; Sun-Ju Song^a ; ^{song@chonnam.ac.kr}
• 关键词：Pd-YSZ cermet hydrogen separation membrane ; Water-splitting ; Ambipolar diffusion ; H2S tolerance ; Self-repairing capability
• 刊名：Ceramics International
• 出版年：2017
• 出版时间：1 February 2017
• 年：2017
• 卷：43
• 期：2
• 页码：2291-2296
• 全文大小：1000 K
• 卷排序：43

文摘

A Pd-YSZ cermet membrane that performs coupled operations of hydrogen separation from a mixed-gas stream and simultaneous hydrogen production by non-galvanic water-splitting, and have high sulfur tolerance is fabricated. It is proved that in H2S containing atmosphere the Pd-YSZ membrane has self-repairing capability, originating mainly from the conversion of Pd4S back to metallic Pd and SO2 by ambipolar-diffused oxygen obtained from water-splitting. The performance of membrane was analyzed at different temperatures in high H2S containing (0–4000 ppm H2S) mixed gas feed during the operation as a hydrogen separation membrane as well as during the coupled operation of hydrogen separation and hydrogen production. At 900 °C with the feed-stream having ≥2000 ppm H2S, the hydrogen flux was severely affected due to the formation of some liquid phase of Pd4S, resulting in the segregation of hydrogen permeating Pd-phase at the membrane surface. But at 800 °C, though the membrane was affected by the Pd4S formation in high H2S environment (up to 1200 ppm H2S), its self-repairing capability and additional hydrogen production by water-splitting is capable of maintaining the hydrogen flux around ~1.24 cm3 (STP)/min.cm2, a value expected by the same membrane while performing only the hydrogen separation function in H2S-free environment.