On Hydrogen “Superstorage“ in Know-How Activated Graphite Nanofibers

The extraordinary, unreproduced data of Rodriguez, Baker, Gupta on the “superstorage” of “reversible” and “irreversible” hydrogen in activated graphite nanofibers are studied using an effective methodology for processing, analyzing and interpretating the thermal desorption and thermogravimetric spectra of hydrogen. The processing of data obtained by Rodriguez makes it possible to determine (by means of two independent methods) the characteristics of the main desorption peak of “irreversible” hydrogen for the first time, namely, the temperature of the highest desorption rate Tmax = 914–950 K, the desorption activation energy Q = 39 ± 3 kJ/mol, the frequency factor of the rate constant of the desorption process K0 ≈ 0.15 s–1, and the amount of evolved hydrogen ~7 wt % corresponding to an atomic ratio of H/C ≈ 0.9. These results can be considered as irrefutable evidence of the “superstorage” of “irreversible” hydrogen in specially activated graphite nanofibers. There is no peak in the thermal-desorption spectra of graphite nanofibers obtained by Rzepka, who unsuccessfully tried to reproduce the extraordinary results of Rodriguez. The presence of a desorption peak is obviously a characteristic feature (attribute) of specially activated graphite nanofibers, which is necessary for the multiple (at least 10 repeated desorption–adsorption cycles at room temperature) “superstorage” of “reversible” hydrogen in them (in the amount of ~20–30 wt %). The physics of the “superstorage” and processes of desorption–adsorption of “reversible” and “irreversible” hydrogen in graphite nanofibers is discussed. The analysis showed that there is a real possibility of reproducing the extraordinary results obtained by Rodriguez, but only in the case of revealing (disclosing) the know-how technology of the activation treatment of graphite nanofibers.