ISOTOPE EXCHANGE AND EQUILffiRA TION REACTION ON NICKEL IN THE SYSTEM DEUTERIUM-LIGHT WATER By

Studies are reported, (i) on the exchange reaction between alkaline solution of light water and pure deuterium or deuterium-containing hydrogen on nickel catalysts with and without cathodic polarization and (ii) on the equilibration reaction between hydrogen and deuterium and the parahydrogen conversion reaction in the same system. From the observed deuterium exchange rates, change in composition of the gaseous hydrogen, and rates of the hydrogen electrode reaction, the following conclusions were drawn: (A) the hydrogen electrode reaction on nickel in alkaline solution obeys the catalytic mechanism; (B) the equilibration reaction between the gaseous hydrogen isotopes as well as parahydrogen conversion reaction take place rapidly, as side reactions, simultaneously with the exchange reaction; and (C) the Langmuir-Hinshelwood mechanism of the equilibration reaction between adsorbed hydrogen molecules best interprete the experimental results obtained on moderately smooth nickel catalysts