NMR Measurement of Exchange of Deuterium between Palladium-Deuteride and Deuterium Gas

作者：Corey Robert L; Cowgill Donald F; Conradi Mark S^*

来源：Journal of Physical Chemistry C, 2012, 116(6): 4335-4339.

DOI：10.1021/jp210839t

Deuterium NMR is used to measure the rate of exchange of D between PdDx (x congruent to 0.7) and the surrounding D-2 gas at thermal equilibrium. In the presence of exchange, the very rapid longitudinal spin relaxation rate of the gas provides an additional path for spin relaxation of the PdDx, beyond the mechanisms intrinsic to the solid deuteride. The measurements reported here extend from -100 to 100 degrees C, with exchange rates from the palladium phase to the gas varying from approximately 0.1 to 200 s(-1). Compared to the PdHx/H-2 system, the PdDx/D-2 system allows a wider range of exchange rates to be probed because of the very low rate of intrinsic longitudinal spin relaxation in PdDx. The activation energy for the exchange rate is found to be 0.32 eV +/- 10%. The data from PdHx is reanalyzed, and a nearly equal energy is found.

• 出版日期2012-2-16