Hydrogen absorption and re-emission characteristics of metal–oxide bi-layer composite materials measured by ion beam analysis

Abstract

Hydrogen absorption and emission characteristics of Pt–Li 2ZrO 3 bi-layer materials exposed to normal air at room temperature have been studied by means of elastic recoil detection analysis(ERD), Rutherford backscattering spectroscopy (RBS), weight gain measurement (WGM) and thermal desorption spectroscopy (TDS). The Pt/Li 2ZrO 3/Pt sandwich specimens have been found to absorb H at the Pt surface from H 2O vapor, store it in Li 2ZrO 3, and emit 80% of it as H 2 gas, when they are heated at 100 °C for 10 min. Data obtained by WGM shows that the weight gain increases linearly with increasing the exposure time. TDS analysis also shows that the main species of gases re-emitted are H 2 and H 2O. Moreover, the hydrogen storage rate in Li 2ZrO 3 is shown to be controlled by the hydrogen absorption rate at the Pt surface, based on the hydrogen absorption and storage model proposed. The maximum storage capacity of Li 2ZrO 3 has been estimated to be 0.15 Nl/cm 3 from the saturation hydrogen concentration, (1/2)H/Li 2ZrO 3, measured by means of the ERD technique.