Hydrogen absorption/desorption behaviors over a quaternary Mg-Ca-Li-N-H system

Hydrogen storage in a quaternary Mg-Ca-Li-N-H system has been investigated by XRD, FT-IR, TPD and PCI. Results showed that hydrogen desorption occurred at temperature about 50 degrees C, and peaked at similar to 178 degrees C under a heating rate of 2 degrees C min(-1). The reversibility of hydrogen storage was observed and the maximum hydrogen storage capacity of about 2.7 wt.% was reached at 220 degrees C and 75 atm. However, the plateau pressure for hydrogen desorption is relatively low (similar to 0.3 atm). Structural identifications reveal that a new phase with tetragonal structure positioned at 31.8 degrees and 51.3 degrees of XRD peaks was generated during hydrogen absorption/desorption. (c) 2006 Elsevier B.V. All rights reserved.