Stability of hydrogenated silica glass and desorption kinetics of molecular hydrogen

Abstract

The stability of saturated solid solutions of molecular hydrogen in silica glass was examined in the temperature range 85 ÷ 175 K by Raman spectroscopy. The kinetics of hydrogen desorption was studied in-situ by tracking time-dependent changes in the intensities of hydrogen rotational modes at an elevated temperature. The heating results in an exponential decrease in the hydrogen content with a temperature dependent time constant. The data at different temperatures are well described by the Arrhenius formula showing the activation character of desorption with the activation energy EA = (0.16 ± 0.01) eV and time constant A = (0.027 ± 0.003) sec.