DEUTERIUM EXCHANGE BETWEEN WATER AND BOEHMITE ($alpha$-ALUMINA MONOHYDRATE). ACTIVATION ENERGY FOR PROTON DIFFUSION IN BOEHMITE
The kinetics of the exchange of D/sub 2/O vapor with crystalline boehmite (particle size ca. 1 ic ) were studied from 85-151 . The Berthier exchange ratio C (number of exchangeable atoms in the solid relative to vapor-phase) ranged from 0.7 to 2.3. The D/sub 2/O pressure was varied from 0.41 to 0.95 atm. A rapid initial surface exchange preceded the slower diffusion- controlled exchange with the bulk crystal. After correction for this surface exchange the data followed the appropriate diffusion equation (spherical particle case). Due to the uncertainty in crystallite size absolute values of the diffusion coefficient D are in doubt by a large (but constant) factor. However, the temperature dependence of D furnishes a reliable value for the activation energy: E = 12.9 sintering time 0.8 kcal./mole. Auxiliary exchange experiments carried out with D/sub 2/O/sup 18/ showed very slow exchange of O/sup 18/ compared to that of deuterium. This suggests independent migration of protons (deuterons) and oxygen carrier ions through the boehmite lattice. (auth)
- Research Organization:
- Univ. of Michigan, Ann Arbor
- Sponsoring Organization:
- USDOE
- NSA Number:
- NSA-13-014325
- OSTI ID:
- 4253614
- Journal Information:
- Journal of Physical Chemistry (U.S.), Journal Name: Journal of Physical Chemistry (U.S.) Vol. Vol: 63; ISSN JPCHA
- Country of Publication:
- Country unknown/Code not available
- Language:
- English
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