I recently prepared ammonia water (likely pure NH3 (aq) ) by placing distilled water (DW) in a large mouth vessel together in a container (which was twice the volume of the DW) loaded with yellow colored household ammonia rich in surfactants, etc. I carefully placed a plug, prepared by wrapping layers of Reynold's Al foil (Al 98% with remainder Fe and Si) around my finger full of NaCl, into the household ammonia and sealed the entire chamber.
The logic is that as NH3 has much reduced solubility in seawater, I expected with time the DW would amass a good amount of the liberated ammonia from the now salt rich household ammonia. A day latter, I opened the vessel, I was surprised to see the amount of bubbling/attack performed on the Al plug, with no heating and no long waiting time (under 12 hours). Favorably, the latter Al attack added H2 gas to increase pressure in the vessel, which to reduce stress in the system, likely further increased the ammonia content of the DW.Note, if one already have some ammonium sulfate, there could try adding it to the vessel with the impure household ammonia/aluminum plug/NaCl. As the formed aluminum hydroxide is amphoteric it may ( Al(OH)3 can be a difficult salt to work with ) actually react with the ammonium sulfate to produce aluminum sulfate and further liberate ammonia.
I viewed this as an inexpensive and successful path to pure aqueous ammonia.
It also indicates that aqueous ammonia is pretty reactive with an Aluminum alloy/NaCl with possibly a Fe presence. Here is a study confirming the attack by chloride ions on industrial Aluminum alloy (see http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.429.4364&rep=rep1&type=pdf ). Even without the transition metal, this result appears to parallel the attack of Al with HNO3 in the presence of NaCl (see https://www.researchgate.net/profile/Vladimir_Petrusevski/publication/215904100_REACTION_OF_ALUMINIUM_WITH_DILUTE_NITRIC_ACID_CONTAINING_DISSOLVED_SODIUM_CHLORIDE_ON_THE_NATURE_OF_THE_GASEOUS_PRODUCTS/links/0f4f8e0daf9ae43bd314f60e/REACTION-OF-ALUMINIUM-WITH-DILUTE-NITRIC-ACID-CONTAINING-DISSOLVED-SODIUM-CHLORIDE-ON-THE-NATURE-OF-THE-GASEOUS-PRODUCTS.pdf ). This last paper makes the strong statement that Al 'dissolves in practically all strong acids' in presence of chloride ions. Likely a similar truth occurs with bases, including aqueous ammonia. Given the electropositive nature of Aluminum metal, some electrochemistry/surface chemistry is likely afoot.
To ever assume that Aluminum is inert with an acid or base in real world applications replete with salt particles, seawater,..., is as foolish as the US Navy was in investing a billion dollars in a fleet of dissolving aluminum hull warships (see https://www.wired.com/2011/06/shipbuilder-blames-navy-as-brand-new-warship-disintegrates/).
