If you want to run your car on aluminum, why not do it with a mechanically recargable battery. You would get nearly 100% of the electrical energy stored in the metal. PEM fuel cells are less than 50% efficient and you would lose even more energy in the chemical process to release hydrogen. You also would have much less complexity and expense.
There have been mechanically recargable marine batteries for about 40 years.
People are just grabbing at straws trying to figure out how to make a hydrogen car.
How would you run an internal combustion engine with your method ?
The point of the article is that this is a method for producing hydrogen on demand that would be useful for internal combustion engines as well as fuel-cells. The Purdue researcher specifically mentions converting existing gasoline engine vehicles to burn hydrogen gas. Which is less efficient than fuel-cells, and much less efficient than an all-electric vehicle, but for which there is a huge base of vehicles.