Influence of temperature and pressure on surface modified Pd-Cu alloy foils for hydrogen purification applications

For the first time, variable temperature X-ray diffraction analysis has been performed on the surface modified foil samples between 30 and 700 °C under 100 and 445 kPa of hydrogen pressure in order to investigate the effects of these conditions on Cu interdiffusion. In general, it was found that under 445 kPa of hydrogen pressure the palladium hydride (β-PdH) phase present in the thin film is stable up to relatively higher temperatures (225 °C) when compared to 100 kPa of hydrogen pressure (150 to 175 °C). In all cases, it was observed that the interstitial solid solution (α-PdH) phase present within the thin film is stable under a significantly narrower temperature range under 445 kPa of hydrogen pressure when compared to 100 kPa of hydrogen pressure.