CALORIMETRIC STUDY OF HYDROGEN REACTION WITH LAVES PHASE C14
Anikina E.Yu.
Lomonosov Moscow State University
119991, Moscow, Leninskie Gory, 1
The initial compounds ZrMn2, ZrMn2.7, Ti0.9Zr0.1Mn1.4V0.7 and Ti0.9Zr0.1Mn1.5V0.8 were synthesized as described in [1]. Thermodynamic studies of the IMС-hydrogen systems were carried out on a DAK-12 calorimeter of the Tiana-Calve type in the temperature range 333 – 518 K and hydrogen pressure up to 5 MPa (see Table).
Temperature dependence of reaction enthalpy for the AB2-H2 system
| Compounds | T, K | Range H/IMC (desorption) | ∆Hdes., kJ/molH2 |
|---|---|---|---|
| ZrMn2 | 373 | 0.1 – 1.9 | 40.16±1.02 |
| 518 | 0.4 – 1.6 | 36.97±0.63 | |
| ZrMn2.7 | 353 | 0.1 – 1.1 | 35.43±0.42 |
| 1.1 – 1.9 | 32.15±0.65 | ||
| Ti0.9Zr0.1Mn1.4V0.7 | 333 | 0.9 – 1.5 | 28.40±0.40 |
| 1.5 – 2.1 | 30.13±0.30 | ||
| 373 | 0.3 – 0.9 | 24.70±0.36 | |
| 1.0 – 2.0 | 30.22±0.43 | ||
| Ti0.9Zr0.1Mn1.5V0.8 | 373 | 0.1 – 0.85 | 30.05±0.45 |
| 1.1 – 1.8 | 36.77±0.91 | ||
| 418 | 0.1 – 0.6 | 28.86±1.41 | |
| 0.6 – 1.6 | 36.30±1.30 |
Enthalpy values of the hydrogen reaction with the IMC change with the temperature of the process under the study and the concentration of hydrogen in the IMC. For ZrMn2-H2 the enthalpy values change only reaction temperature, but it does not depend on the hydrogen content in the IMC. In ZrMn2.7-H2 there are two sections where the enthalpy values are constant. For Ti0.9Zr0.1Mn1.4V0.7-H2band Ti0.9Zr0.1Mn1.5V0.8-H2 systems the enthalpy values change with reaction temperature and hydrogen concentration moreover an increase in hydrogen concentration is accompanied by an increase in the reaction enthalpy.
1. Anikina E.Yu., Verbetsky V.N. //J. Alloys Compd. 2002. V. 330-332. P. 45. https://doi.org/10.1016/S0925-8388(01)01509-2
The study was conducted under the state assignment of Lomonosov Moscow State University, project 122012400186-9.