Hydrogen permeation through a Pd/Ta composite membrane with a HfN intermediate layer
Hydrogen permeation through a Pd/Ta composite membrane with a HfN intermediate layer
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DOI：
10.1016/j.ijhydene.2013.07.012
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发表时间：
2013-09
影响因子：
7.2
通讯作者：
T. Nozaki;Y. Hatano
中科院分区：
文献类型：
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作者：
T. Nozaki;Y. Hatano
在复合氢分离膜中，在Pd保护膜和Ta基底之间制备致密的氮化铪（HfN）层，以防止Pd和基底在高温下发生反应。对于具有 50 nm 厚 HfN 层的膜，在 873 K 下经过至少 35 小时，没有观察到氢渗透率显着降低，而没有 HfN 层的样品在 5 小时内迅速劣化。前一个样品的稳态氢渗透率在 873 K 时为 4 × 10−9mol m−1s−1Pa−0.5。该值比Pd覆盖的Ta劣化前的初始磁导率小一个数量级。使用 HfN 粉末样品测量压力-成分等温线表明，氢在 HfN 中的溶解度足够高，与 Ta 中的溶解度相当。因此，HfN 中间层观察到的低渗透率归因于 HfN 中氢的低扩散率。
Dense hafnium nitride (HfN) layers were prepared between Pd protection films and a Ta substrate in a composite hydrogen separation membrane to prevent a reaction between the Pd and the substrate at high temperatures. No significant reduction in hydrogen permeation rate was observed for the membrane with 50-nm-thick HfN layers at 873 K through at least 35 h, whereas the specimen without HfN layers rapidly deteriorated within 5 h. Hydrogen permeability of the former specimen was 4 × 10−9mol m−1s−1Pa−0.5at 873 K at steady state. This value was smaller than the initial permeability of Pd-covered Ta before deterioration by an order of magnitude. The measurements of pressure–composition isotherms by using a HfN powder specimen showed that the hydrogen solubility in HfN was sufficiently high and comparable with the solubility in Ta. Therefore, the low permeability observed with the HfN intermediate layers was ascribed to low hydrogen diffusivity in HfN.