scholarly journals Sodium Isotopic Exchange Rate between Disodium Zirconium(IV) Bis(orthophosphate) Trihydrate and Aqueous Solutions

1983 ◽  
Vol 56 (3) ◽  
pp. 705-708 ◽  
Author(s):  
Yasushi Inoue ◽  
Yoshimune Yamada
Keyword(s):  
Exchange Rate ◽  
Aqueous Solutions ◽  
Isotopic Exchange

Solubility, Diffusivity, and Isotopic Exchange Rate of Hydrogen Isotopes in Li-Pb

2008 ◽  
Vol 54 (1) ◽  
pp. 131-134 ◽  
Author(s):  
Y. Maeda ◽  
Y. Edao ◽  
S. Yamaguchi ◽  
S. Fukada
Keyword(s):  
Exchange Rate ◽  
Isotopic Exchange ◽  
Hydrogen Isotopes

Hydrogen isotopic exchange between D2 and H2O on alumina prepared by sputtering

1993 ◽  
Vol 71 (5) ◽  
pp. 663-669 ◽  
Author(s):  
Fumio Ioka ◽  
Tetsuo Sakka ◽  
Yukio Ogata ◽  
Matae Iwasaki
Keyword(s):  
Exchange Rate ◽  
Isotopic Exchange ◽  
Molecular Orbital Calculations ◽  
Base Pairs ◽  
Coordination Numbers ◽  
Rate Determining Step ◽  
Heat Treated ◽  
The Exchange Rate ◽  
Low Pressures ◽  
Oxygen Site

Hydrogen isotopic exchange between D2 and H2O has been investigated on alumina prepared by sputtering at 803 K and at low pressures. The alumina is amorphous, consisting of aluminum with coordination numbers four, five, and six in the ratio 1:2:1 as determined by NMR. A kinetic model is proposed on the basis of the pressure dependence of the exchange rate and the heats of adsorption at adsorbed sites, evaluating by molecular orbital calculations. The adsorbed sites are assumed to be Lewis acid–base pairs composed of a coordinatively unsaturated aluminum and the adjacent unsaturated oxygen site. The site relating to the rate-determining step contains threefold aluminum, which is formed by unsaturation of fourfold aluminum at the surface. As a consequence, the exchange rate depends on the amount of fourfold aluminum when the alumina is heat treated and changes its phase.

Sign in / Sign up

Export Citation Format

Share Document