NewScientist (12 August 2017) reports on an unexpected chemical reaction may revive hydrogen fueled cars:
Earlier this year, Scott Grendahl and his team at the US Army Research Laboratory at Aberdeen Proving Ground in Maryland made a surprising discovery. They were testing a high-strength aluminium alloy by pouring water on it, and it started to bubble, giving off hydrogen. That doesn’t normally happen to aluminium. It usually oxidises in water, forming a barrier that stops any reaction. But this alloy just kept reacting.
Hydrogen has long been touted as a clean, green fuel, but it is difficult to store and move around because of the low temperature and high pressure at which it must be kept. If aluminium could be made to effectively react with water, it would mean hydrogen on demand. Unlike hydrogen, aluminium and water are easy to carry, and both are stable. But previous attempts to get aluminium and water to react required high temperatures or catalysts, and were slow. Obtaining the hydrogen took hours and was around 50 per cent efficient.
“Ours does it in less than 3 minutes,” says Grendahl. Moreover, the new material offers at least an order of magnitude more energy than lithium batteries of the same weight. And unlike batteries, it can remain stable and ready for use indefinitely.
So is the aluminium alloy consumed by the reaction? Or is it a catalyst itself?
Maybe I should hang on to my Mazda RX7 – I recall reading quite a long time ago that Mazda engineers had adapted the car’s rotary engine to use hydrogen rather than gasoline. Just pour in the distilled water…
