Hydrogen absorption–desorption isotherms of La(28.9)Ni(67.55)Si(3.55)

Pressure–composition–temperature (P–C–T) isotherms of La(28.9)Ni(67.5)Si(3.55) which was fabricated by substitution of Ni by Si in LaNi5 at different temperature has been studied in the present work. It was found that the activation of the alloy is sufficiently easy. The saturation value of H/M of this alloy is about 1.0 for P–C–T at room temperature (293 K). The H/M values were found to be 0.9, 0.85, 0.8 for P–C–T isotherms at 313, 323, 333 K, respectively, and equilibrium pressures were 1.01×105, 1.41×105, 1.71×105, 2.12×105 Pa at these temperatures. The investigations show that the wt% of hydrogen in the alloy was about 1.75%. The maximum amount of hydrogen released by the alloy is in the temperature range 313–343 K. For P–C–T curves the α+β phase decrease at higher temperatures. This makes it a better alloy for hydrogen storage for technological applications than LaNi5.