Effect of the storage environment on hydrogen production via hydrolysis reaction from activated Mg-based materials

The reaction performance of activated Mg/CoCl2 has been studied relative to its storage time, temperature, RH (relative humidity), and storage methods. Activated Mg/CoCl2 was prepared via high-energy milling and characterised using SEM (scanning electron microscopy) and TG (thermogravimetric analysis). The samples were aged for 30 days at different RH and temperatures. Three different methods were used to store the powders at 30 °C and 60% RH. The results showed that the efficiency decreased rapidly when the storage time increased, and the highest hydrogen generated rate decreased dramatically from 41.0 to 2.0 ml s−1 g−1 after 1 day, reaching 0.7 ml s−1 g−1 after 30 days at 60% RH and 20 °C. The efficiency of the sample decreased more in warmer and more humid atmospheres. The efficiency of the sample stored in the Ziploc bag remained almost unchanged during the first five days before decreasing from 81.9% to 66.5%. As expected, the efficiency only decreased 1.5% after 30 days in the Snap-Cap Centrifuge tube. •Activated Mg/CoCl2 composites are prepared by high-energy milling.•The Mg/CoCl2 composite is very promising for hydrogen generation.•The age-related effects caused by the temperature and humidity are studied.•The efficiency of Mg/CoCl2 decreases rapidly when the storage time increase.•The efficiency of Mg/CoCl2 decreases more at higher temperature or humidity.