AB5-type intermetallic compounds for biohydrogen purification and storage

Intermetallic compounds (IMC) provide a promising solution for a biohydrogen purification problem due to their selective hydrogen absorption from gaseous mixtures produced during dark fermentation. A main IMC characteristic for use in biohydrogen purification is hydrogen equilibrium pressure, which has to be as low as possible during hydrogen sorption from a mixture. Intermetallic compounds LaNi5-xMx (M−Al, Sn, Fe; x = 0.1-0.3) were prepared and their PCT properties were investigated. Compositions LaNi4.6Fe0.2Al0.2 (0.049 MPa at 293 K) and LaNi4.6Sn0.2Fe0.2 (0.055 MPa at 293 K) are found to be the most promising for practical applications due to low equilibrium pressures.