Compensation effect in H 2 permeation kinetics of PdAg membranes

Gaofeng Zeng, Andreas Goldbach, Lei Shi, Hengyong Xu

Research output: Contribution to journalArticlepeer-review

16 Scopus citations


Knowledge about the (inter)dependence of permeation kinetic parameters on the stoichiometry of H 2-selective alloys is still rudimentary, although uncovering the underlying systematic correlations will greatly facilitate current efforts into the design of novel high-performance H 2 separation membranes. Permeation measurements with carefully engineered, 2-7 μm thick supported Pd 100-xAg x membranes reveal that the activation energy and pre-exponential factor of H 2 permeation laws vary systematically with alloy composition, and both kinetic parameters are strongly correlated for x ≤ 50. We show that this permeation kinetic compensation effect corresponds well with similar correlations in the hydrogen solution thermodynamics and diffusion kinetics of PdAg alloys that govern H 2 permeation rates. This effect enables the consistent description of permeation characteristics over wide temperature and alloy stoichiometry ranges, whereas hydrogen solution thermodynamics may play a role, too, as a yet unrecognized source of kinetic compensation in, for example, H 2-involving reactions over metal catalysts or hydrogenation/ dehydrogenation of hydrogen storage materials. © 2012 American Chemical Society.
Original languageEnglish (US)
Pages (from-to)18101-18107
Number of pages7
JournalThe Journal of Physical Chemistry C
Issue number34
StatePublished - Aug 21 2012

Bibliographical note

KAUST Repository Item: Exported on 2020-10-01

ASJC Scopus subject areas

  • Surfaces, Coatings and Films
  • General Energy
  • Physical and Theoretical Chemistry
  • Electronic, Optical and Magnetic Materials


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