Permeation Hysteresis in PdCu Membranes
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- 作者：Lixiang Yuan ; Andreas Goldbach ; Hengyong Xu
- 刊名：Journal of Physical Chemistry B
- 出版年：2008
- 出版时间：October 9, 2008
- 年：2008
- 卷：112
- 期：40
- 页码：12692-12695
- 全文大小：131K
- 年卷期：v.112,no.40(October 9, 2008)
- ISSN：1520-5207
文摘
H2 permeation hysteresis has been observed during cycling of a 3 μm thick supported PdCu membrane with ∼50 atom % Pd through the fcc/bcc (face-centered cubic/body-centered cubic) miscibility gap between 723 and 873 K. Structural investigations after annealing of membrane fragments under H2 at 823 K reveal retardation of the fcc(H) → bcc(H) transition, which is attributed to the occurrence of metastable hydrogenated fcc PdCu(H) phases. The H2 flux at 0.1 MPa H2 pressure difference in the well-annealed bcc single phase regime below 723 K can be described by JH2 = (1.3 ± 0.2) mol·m−2·s−1 exp[(−11.1 ± 0.6) kJ·mol−1/(RT)] and that in the fcc single phase regime above 873 K by JH2 = (7 ± 2) mol·m−2·s−1 exp[(−30.3 ± 2.5) kJ·mol−1/(RT)].