A thermal calorimetric investigation on potentially high-density hydrogen storage materials

In this paper, a calorimetric study of solid ammonium formate (NH 4 HCO 2 ) is experimentally performed using a Parr 6775 oxygen bomb calorimeter. The experimental measurements indicate that a temperature increase of 1.51 °C occurs in 2 kg ±0.001 kg of water, which corresponds to a total heat release of 15.122 kJ is observed for a 2 g of ammonium format sample. The specific and molar heats of combustion are then determined as 7.56 kJ/g (or 7560 kJ/kg) and 476.6 kJ/mol (476,600 kJ/kmol), respectively. The calculated heating value of ammonium formate is 551.8 kJ/mol which is in a reasonable agreement with the experimental measurement with a difference of 15.7%. The difference may be attributed to the losses during the experiment and the production stage of ammonium formate. Furthermore, these experimental observations provide positive results regarding its heating value, thermochemical stability and combustion behavior and demonstrate the operation of hydrogen release mechanisms during combustion potential use of this material in the future for solid hydrogen storage research and system-level evaluations.