Some observations related to the presence of hydrogen and deuterium in palladium

Surface and bulk analytical work carried out on palladium rod samples returned to Johnson Matthey by Fleischmann and Pons indicates that a number of elements, including platinum and lithium were deposited on the surface during electrolysis in D2O. Surface analysis via time of flight SIMS indicates that the Li6/Li7 isotope ratio is unusually low but no original reference is available. One electrolyzed rod exhibited recovery of part of the wrought microstructure which would ordinarily require a temperature of > ca. 200degC, and another rod showed recrystallization of a portion of its length and this would normally require a temperature of > ca 300degC. These effects, which were observed at the ends of the rods away from the spot welds, cannot readily be explained by known processing history, and could not be reproduced by filing or sawing. Temperature programmed hydrogen absorption/desorption profile measurements on a range of palladium samples indicate wide differences in properties; for example a rod electrolyzed in aqueous LiOH solution absorbed hydrogen more readily than a similar rod electrolyzed in aqueous NaOH. This technique would therefore seem to be of value in characterizing the palladium electrode. Electrochemical measurements conducted in H2O show that there are significant differences between the behaviour of Pd in LiOH, and in NaOH and KOH solutions. (author)