Investigation on environmental stability and hydrolytic hydrogen production behavior of Mg30La alloy modified by activated carbon/ expandable graphite

In the process of hydrogen production, Mg-based alloy is easily poisoned by the environ-ment to form an inert oxide layer. The effect of carbon catalysts (AC,EG) on the environmental stability of short time high energy ball milling Mg30La alloy is explored by simulating the real environmental toxic conditions. The toxicity of Mg30La alloy with oxygen and oxygen without water and the anti-toxicity ability after surface modification are reported. The results show that Mg30La alloy has the highest initial hydrogen production rate before exposure, and the average rate is 88.66 mL g-1$min-1 in the first 5 min. But Mg30La-EG has a higher yield, reaching 91% at 60 min, 18% higher than that of Mg30La alloy without catalysis. The yield of Mg30La-AC is only 55% at 60 min. After the sample is exposed, the hydrolyzed hydrogen production test show that Mg30La-EG has a higher initial hydrogen production rate than Mg30La, reaching 87.5 mL g ?1 center dot min ?1 in the first 2 min. However, Mg30La alloy has the highest hydrogen production capacity, 21% higher than Mg30La-AC and 20% higher than Mg30La-EG. In summary, after adding AC, the adsorption of activated carbon will lead to the formation of an inert layer on the surface, thus affecting the hydrolytic hydrogen production performance. However, after adding EG, hydrogen can be rapidly produced at room temperature, and the yield of Mg30La alloy can be significantly improved. However, long-term contact with the environment should be avoided before hydrogen production to ensure low temperature, rapid and efficient hydrogen production.(c) 2023 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.