摘要
LaNi4.70Al0.30 was characterized by SEM, EDS and XRD. The structure was refined by the Rietveld method. The intermetallic stability temperature range in air was analyzed by DSC. The intermetallic is destabilized at T聽>聽160掳 C. The intermetallic was annealed at this temperature for 24聽h in air. After that, the pressure-composition-isotherms were measured. The thermodynamic properties were calculated from the Van鈥檛 Hoff diagrams. Values obtained were 螖Hf聽=聽30聽卤聽2聽kJ/mol and 螖Sf聽=聽0.13聽卤聽0.01聽kJ/mol for absorption process and 螖Hd聽=聽31聽卤聽2聽kJ/mol and 螖Sd聽=聽0.14聽卤聽0.01聽卤聽kJ/mol for desorption process. From these results, a scheme of thermal compression of hydrogen (TCH) was proposed. The scheme has a practical compression ratio (Rc) of 7.2 in the 25-100聽掳C temperature range and 1-1000聽kPa pressure range.