Investigation on performances of the novel ammonia-based hydrogen storage material CaCl2

Ammonia absorption/desorption properties of CaCl2 and effects of the operation temperature, starting pressure and ball milling treatment were investigated. The post-2h milled sample can be fully ammoniated to form CaCl2(NH3)(8) within 15min under 20 degrees C and 0.55MPa, and the ammonia storage capacity is 55.1wt%, equivalent to be 9.72 wt% of hydrogen. NH3 can be desorbed from CaCl2(NH3)(8) in the temperature range from 20 degrees C to 300 degrees C with three stages controlled by temperature and pressure. Six NH3 molecules can be desorbed at ambient temperature and pressure. Combined with NH3 decomposition catalyst, CaCl2 may be one of promising ammonia-based hydrogen storage materials with high capacity. Further investigations indicate that higher operation temperature and starting pressure can improve the ammonia absorption kinetics of CaCl2, and prolonging ball-milling time can decrease the operation temperature for ammonia desorption of CaCl2(NH3)(8) and improve its ammonia desorption kinetics.