a real good fuel cell will convert and generate energy at 90% efficiency (very high), if you used the energy collected in the hydrogen fuel cell to simply break more water you would be still losing energy, and you are adding a motor to the equation. i still say that aluminum-nickel alloy would still not be as good as platinum, especially carrying out the process that you are thinkin about, using the same energy to break apart more hydrogen, i think it would be easier to get a very small solar panel, which would only weight a few grams, and would carry out the process very efficiently.
well i found one of the components in the storage tank found here:
http://www.fuelcellstore.com/cgi-bin/fuelweb/view=Item/cat=5/product=128its palladium at 99.99% purity. the amazing aspect of palladium is that it is capable of storing 900 times its own volume of hydrogen. such that if i am not mistaken 1 gram would hold 900 cm
3 of H
2now there is something else that other researches have been investigating, and that is graphite. one site gave the figures of holding hydrogen as 30 liters per gram of graphite separate at something like 1 billionth of a meter (not sure about the separate part). when i did the calculation i got one almost impossible to believe answer, which makes me think that i am doing something terribly wrong and that i have to review the chapter dealing with volume..
1 liter is 1000cm
3 right?
if so then that would mean that graphite is capable of holding 30000cm
3 of H
2, which means that it is a very inexpensive material capable of holding more than 1 mole of hydrogen for 1/12
th of a mole of graphite, and that if used as a storage container it would solve one of the major problems with fuel cells and gives a solution. but my question now is how would the hydrogen be extracted, do you need heat? if so how much? and what kind of container is used to hold palladium or graphite and hydrogen at the same time? If someone can help me out here it would greatly be appreciated, trying to make a car as a school project and it would really be helpful to know all this stuff?