Palladium mixed-metal surface-modified AB5-type intermetallides enhance hydrogen sorption kinetics

• Main Authors: Mario Williams, Mykhaylo Lototsky, Alexander Nechaev, Volodymyr Yartys, Jan, Roman Denys, Vladimir Linkov
• Format: Article
• Language: English
• Published: Academy of Science of South Africa 2010-10-01
• Series: South African Journal of Science
• Online Access: http://192.168.0.115/index.php/sajs/article/view/9922

Surface engineering approaches were adopted in the preparation of advanced hydrogen sorption materials, based on 'low-temperature', AB5-type intermetallides. The approaches investigated included micro-encapsulation with palladium and mixed-metal mantles using electroless plating. The influence of micro-encapsulation on the surface morphology and kinetics of hydrogen charging were investigated. It was found that palladium-nickel (Pd-Ni) co-deposition by electroless plating significantly improved the kinetics of hydrogen charging of the AB5-type intermetallides at low hydrogen pressure and temperature, after long-term pre-exposure to air. The improvement in the kinetics of hydrogen charging was credited to a synergistic effect between the palladium and nickel atoms in the catalytic mantle and the formation of an 'interfacial bridge' for hydrogen diffusion by the nickel atoms in the deposited layer. The developed surface-modified materials may find application in highly selective hydrogen extraction, purification, and storage from impure hydrogen feeds.