Tuesday, December 8, 2009

Could Your Car Run on Vitamin C?

OK, not like putting vitamin C in your car and having it run on that, but with a middleman: vitamin C feeds a molecular engine that makes hydrogen, and THAT fuels your car. Here is the outline of events:

1.) Vitamin C (ascorbate) gives electrons to cytochrome c. (It has enough "energy" that this would work.)
2.) Cytochrome c gives electrons to photosystem I. (That's its job after all!)
3.) Light excites the electrons in photosystem I. (Again, that's its job.)
4.) The electrons move to platinum clusters on the other side of the photosystem.
5.) Platinum catalyzes the conversion of acid protons to hydrogen gas.
6.) Hydrogen gas carries the "light energy" anywhere it goes (and when burned in a car produces water vapor as the waste!).

The especially good news: this scheme (shown above) self-assembles and runs for months without help. Not sure how much platinum it needs ... but at least as a catalyst it's not consumed.

I'm getting more and more keen on hydrogen as a versatile fuel, if we can just solve the storage problem. This shows just how easy it is to make it. Storing it is a bigger problem, but it doesn't seem insurmountable (easy for me to say, I don't research that!).


Kalani said...

My question is how much energy is used to maintain the acid source? At some point you will run out of protons and will need to replenish them. Is there a way to make this sustainable?

Ben McFarland said...

That's the beauty of vitamin C: it's ascorbic ACID, right? And you can tune the proton availability with the right buffer. Living things are good at making protons and at making things like vitamin C -- that's why this is pretty darn cool.