The hydrogen/deuterium sorption properties of Ni33Ti39Nb28 synthesized by the vacuum induction melting technique were measured between 400 and 495 C for pressure lower than 3 bar. The Sieverts law is valid up to H(D)/M < 0.2 in its ideal form; the absolute values of the hydrogenation/ deuteration enthalpy are DH(H2) = 85+-5 kJ/mol and DH(D2) = 84+-4 kJ/mol. From the kinetics of absorption, the diffusion coefficient was derived, and an Arrhenius dependence from the temperature was obtained, with Ea,d = 12+-1 kJ/mol for both hydrogen isotopes. The values of the alloy permeability, obtained by combining the solubility and the diffusion coefficient, were of the order of 10^(-9) mol m^(-1) s^(-1) Pa^(-0).5, a value which is one order of magnitude lower than that of Ni41Ti42Nb17, until now the best Ni-Ti-Nb alloy for hydrogen purification. In view of the simplicity of the technique here proposed to calculate the permeability, this method could be used for the preliminary screening of new alloys.
Hydrogen and Deuterium Solubility, Diffusivity and Permeability from Sorption Measurements in the Ni33Ti39Nb28 Alloy / Palumbo, Oriele; Trequattrini, Francesco; Tosti, Silvano; Santucci, Alessia; Paolone, Annalisa. - In: MOLECULES. - ISSN 1420-3049. - 28:3(2023), p. 1082. [10.3390/molecules28031082]
Hydrogen and Deuterium Solubility, Diffusivity and Permeability from Sorption Measurements in the Ni33Ti39Nb28 Alloy
Trequattrini, Francesco;
2023
Abstract
The hydrogen/deuterium sorption properties of Ni33Ti39Nb28 synthesized by the vacuum induction melting technique were measured between 400 and 495 C for pressure lower than 3 bar. The Sieverts law is valid up to H(D)/M < 0.2 in its ideal form; the absolute values of the hydrogenation/ deuteration enthalpy are DH(H2) = 85+-5 kJ/mol and DH(D2) = 84+-4 kJ/mol. From the kinetics of absorption, the diffusion coefficient was derived, and an Arrhenius dependence from the temperature was obtained, with Ea,d = 12+-1 kJ/mol for both hydrogen isotopes. The values of the alloy permeability, obtained by combining the solubility and the diffusion coefficient, were of the order of 10^(-9) mol m^(-1) s^(-1) Pa^(-0).5, a value which is one order of magnitude lower than that of Ni41Ti42Nb17, until now the best Ni-Ti-Nb alloy for hydrogen purification. In view of the simplicity of the technique here proposed to calculate the permeability, this method could be used for the preliminary screening of new alloys.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
