Hydrogen absorption behavior of a Pd-coated Zr70Fe5.4V24.6 getter material against gaseous impurities

In this work, Pd coating has been deposited on a Zr70Fe5.4V24.6 getter alloy by electroless plating technique. It is expected to illustrate the role of Pd coating on hydrogenation properties of Zr70Fe5.4V24.6 against gaseous impurities. X-ray diffraction and SEM observations along with EDS give the evidences that the Pd coating has been uniformly deposited on the surface of the Zr70Fe5.4V24.6 alloy. Hydrogenation properties of Zr70Fe5.4V24.6 in pure H₂ and/or H₂ containing 1 vol.% air are examined by using a Sieverts-type apparatus. Gaseous impurities significantly reduce the hydrogen storage capacity of Zr70Fe5.4V24.6. In pure hydrogen, Pd coating improves the hydrogenation rates of Zr70Fe5.4V24.6 by 31% without losing the maximum hydrogen absorption capacity. Electroless plated Pd coating also improves hydrogenation rates of Zr70Fe5.4V24.6 in hydrogen with 1 vol.% air gaseous impurities without losing hydrogen absorption capacity. Meanwhile, the oxidation of Pd coated Zr70Fe5.4V24.6 can be obviously reduced during hydrogenation in hydrogen with gaseous impurities. XPS investigations indicate that the amount of zirconium sub-oxide on the surface of the Pd-coated alloy is ∼12% lower than that of the alloy without Pd coating. Electroless plated Pd coating has been proven to efficiently improve hydrogenation kinetics and poisoning tolerance of Zr70Fe5.4V24.6 against gaseous impurities.