Analysis and improvement of cyclic stability of H2sensing properties of Pd/Mg-Ni films

Y. M. Tang, Chung Wo Ong

Research output: Journal article publicationJournal articleAcademic researchpeer-review

7 Citations (Scopus)

Abstract

The nominal electrical resistivity of palladium coated magnesium-nickel (Pd/Mg-Ni) films was measured by exposing the films iteratively to hydrogen (H2) at a concentration of CH2for hydrogenation and air for dehydrogenation. When a low CH2was used, the film remained in an amorphous α-phase. H atoms interacted "interstitially" with the atomic network, and the H2detection sensitivity S was relatively stable in the cyclic test. If higher CH2values were used, the film was partially or completely transformed to an amorphous β-phase. Significant volumetric breathing occurred in the course, leading to severe roughening of the film and oxidation of the Mg-Ni layer. S became unstable. These suggestions are supported by the results of film thickness measurements, atomic force microscopy and X-ray photoelectron spectroscopy analyses. Stability of S of a Pd/Mg-Ni film can be greatly improved by either (i) operating the film in a low CH2environment to prevent substantial volume breathing, or (ii) choosing an appropriate thickness of the Pd layer to optimize both oxidation resistance and sensing response of the film sensor.
Original languageEnglish
Pages (from-to)10188-10196
Number of pages9
JournalInternational Journal of Hydrogen Energy
Volume36
Issue number16
DOIs
Publication statusPublished - 1 Aug 2011

Keywords

  • Cyclic stability
  • H sensing properties 2
  • Magnesium-nickel alloy films

ASJC Scopus subject areas

  • Renewable Energy, Sustainability and the Environment
  • Fuel Technology
  • Condensed Matter Physics
  • Energy Engineering and Power Technology

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