Metal amidoboranes have been regarded as potential candidates for hydrogen storage applications, due to their high gravimetric capacities and their relatively low hydrogen desorption temperatures. Here, we report about the synthesis of calcium amidoborane (CaAB) by means of reactive milling of ammonia borane and calcium hydride. Structural properties and hydrogen desorption behavior of samples, prepared with different Milling times and after aging for long periods in an inert atmosphere, have been investigated by X-ray powder diffraction, thermal programmed desorption and differential scanning calorimetry. It has been observed that CaAB spontaneously decomposes during aging at room temperature giving rise to the formation Of an amorphous phase product. The observed sample metastability has a strong effect on the hydrogen desorption behavior of CaAB and give place to complex changes in the hydrogen desorption kinetics as well as in desorption enthalpies.
Hydrogen Desorption Behavior of Calcium Amidoborane Obtained by Reactive Milling of Calcium Hydride and Ammonia Borane / Leardini, Fabrice; J. R., Ares; J., Bodega; M. J., Valero Pedraza; M. A., Banares; J. F., Fernandez; C., Sanchez. - In: JOURNAL OF PHYSICAL CHEMISTRY. C. - ISSN 1932-7447. - 116:46(2012), pp. 24430-24435. [10.1021/jp307204b]
Hydrogen Desorption Behavior of Calcium Amidoborane Obtained by Reactive Milling of Calcium Hydride and Ammonia Borane
LEARDINI, FABRICE;
2012
Abstract
Metal amidoboranes have been regarded as potential candidates for hydrogen storage applications, due to their high gravimetric capacities and their relatively low hydrogen desorption temperatures. Here, we report about the synthesis of calcium amidoborane (CaAB) by means of reactive milling of ammonia borane and calcium hydride. Structural properties and hydrogen desorption behavior of samples, prepared with different Milling times and after aging for long periods in an inert atmosphere, have been investigated by X-ray powder diffraction, thermal programmed desorption and differential scanning calorimetry. It has been observed that CaAB spontaneously decomposes during aging at room temperature giving rise to the formation Of an amorphous phase product. The observed sample metastability has a strong effect on the hydrogen desorption behavior of CaAB and give place to complex changes in the hydrogen desorption kinetics as well as in desorption enthalpies.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
