Interaction of graphite with atomic hydrogen

The kinetics of sorption of atomic hydrogen by pyrolytic, quasi-single-crystal, and RGT commercial-grade graphite was studied. The processes of sorption and subsequent thermal outgassing are shown to proceed in a similar manner for all the three types of graphite. Thermal desorption spectra obtained during linear heating of hydrogen-saturated samples have two peaks. A mathematical model including features of the thermal desorption kinetics that are observed when heating is terminated is suggested. According to this model, two types of traps with binding energies of 2.4 and 4.1 eV are present in graphite. The physical justification of the model is given. (C) 2001 MAIK Nauka/Interperiodica.