Kinetics of hydrogen absorption of tantalum coated with thin films of palladium, iron, nickel, copper and silver

Abstract

The effects of coatings of palladium, nickel, iron, copper and silver on the kinetics of hydrogen atom absorption of tantalum wires were measured in the temperature range 300–700 K. Thin palladium coatings were the most effective and yielded absorption rates that were near the theoretical value for a diffusion-controlled reaction mechanism. This corresponds to an enhancement factor of 10 4 or more at room temperature. Nickel and iron films increased the reaction rate by one to two orders of magnitude but copper and very thin silver films yielded no pronounced improvement of the small absorption rates of hydrogen on tantalum below 500 K.