Studies on the potential of ionisation of diffused heavy hydrogen at Pd/alkaline solution interface

The uncertainty with regard to the value of the exact potential or range of potentials for ionising the diffused hydrogen at a Pd 0.2 N NaOH solution interface using the Devanathan and Stachurski electropermeation technique has been solved recently and it has been established that -300 mV with respect to Hg/HgO-0.2 M NaOH is the most suitable potential. The aim of this investigation is to test whether or not the same potential is applicable for the ionisation of heavy hydrogen at the same interface. It is found that the plateau between -200 and -350 mV represents the actual region of ionisation of heavy hydrogen. The plateau region between +350 and +500 mV has been attributed to palladium oxide formation. Hence a potential of -300 mV with respect to Hg/HgO, 0.2 M NaOH electrode corresponding to the mid region of the plateau has been chosen as the most suitable potential for ionising diffused heavy hydrogen most efficiently. (author)