On mechanism of hydrogen generation at oxidation of activated aluminum in aqueous solutions

To clarify the mechanism of hydrogen generation upon aluminum oxidation by water, the behavior of the mechanical alloys {Al+20%Bi} and {Al+7%Ga+3%In} in various salt solutions has been studied. Analysis of the reaction rate and the overall hydrogen yield in the studied systems allows us to suggest that, unlike the oxidation of magnesium-based materials, the hydrogen generation by activated aluminum is not mainly controlled by electrochemical processes. Additives of activating metals, bismuth and gallium-indium alloys, primarily act as surfactants, making an unoxidized intergranular surface accessible to water according to the Rebinder effect.