Reaction with Urushibara Catalyst

I'm not a chemist, nor an organic chemistry student, but I do a lot of research. I have a question about the end of [this synthesis](https://www.erowid.org/archive/rhodium/chemistry/amph.urushibara.html).



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> Dissolve 5g pure phenylnitropropene in 50ml Ethanol and add to Ni solution.2 Now slowly add 3ml conc. HCl3 and 1 gram shredded aluminum w/ manual stirring. Aluminum will slowly dissolve with a more vigorous effervescence of hydrogen than the first step. Maintaining good stirring with a glass stirring rod is essential in beginning. Attempted magnetic stirring will result in frustration because nickel is ferromagnetic and will stick to stirbar preventing surface area exposure necessary for reduction. After aluminum is dissolved add three more milliliters HCl and one more gram Al. Repeat adding acid and Al until 10 grams Al and about 30ml HCl has been added. Aluminum reacts slowly. Expect addition to take about six hours, longer if temp falls below 50°C. Constant stirring towards end is not necessary, just give mix a good stir occasionally.
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My understanding is that the aluminum is being added to hydrochloric acid in order to create hydrogen gas, which will adsorb to the U-Ni-A catalyst. This then allows for the hydrogenation of that double bond in P2NP, AND the reduction of the nitro group to an amine group simultaneously? Or does the aluminum serve some other purpose than to just create hydrogen gas? Or is that not what's happening at all?


If I'm completely off I'd love a step by step of what's going on here, or some key words/processes for me to look up.


