Effects of temperature and hydrogen pressure on the activation behavior of ZrCo

• Effects of temperature and H2 pressure on activation process of ZrCo were studied.
• Optimum procedures were obtained for fast and efficient activation of ZrCo.
• Optimum procedures included initial evacuation, hydrogen absorption and desorption.

Fast and efficient activation of ZrCo is beneficial to promote its application to hydrogen isotopes storage in the fusion energy field. To obtain the optimum activation procedures, the influences of temperature and hydrogen pressure on the activation behavior of ZrCo were systematically investigated. Experimental results showed that fast and efficient activation of ZrCo could be achieved by optimizing the temperature and hydrogen pressure conditions of the activation procedures including initial evacuation, hydrogenation and dehydrogenation. It was found that initial evacuation at temperature higher than 300 °C was clearly beneficial to the subsequent hydrogenation process. Hydrogen absorption rate of ZrCo during the activation process could be enhanced by increasing the hydrogenation temperature, whereas hydrogen pressures had an indiscernible impact on the hydrogenation process. Compared with other temperatures and hydrogen pressures, 100 °C and 0.8 bar H2 was a preferred condition for hydrogenation of ZrCo. In addition, it was demonstrated that dehydrogenation at high temperature over 500 °C was favorable to enable activated ZrCo to own high hydrogen capacity. As a result, optimum procedures composed of initial evacuation at 500 °C, hydrogenation at 100 °C under 0.8 bar H2 and dehydrogenation at 500 °C under vacuum were highly recommended for fast and efficient activation of ZrCo.