THE ELEMENT OF THE DAY

The race to end our dependence on fossil fuels is on. With the cost of heating our homes and driving our cars at an all time high, I think people are finally ready for the change. But how close are we? Scientists have been arguing for a long time that hydrogen would make an excellent alternative fuel. Todd Livingston, an electronics technician from Boston, plans to use lasers to capture lightning bolts and then channel them through large tanks of water to produce hydrogen. Sounds like a novel idea, but knowledgeable scientists say that it probably won’t work because so far lasers can’t capture lightning.

The problem with hydrogen is that it’s a gas, which means it has less energy per volume as liquid fuels. You’d need a lot of it to run a car and probably need a tank four times the size of you vehicle to store enough hydrogen to get any where. The key to caging hydrogen lies in metallic-organic framework compounds (MOFs). MOFs are nano-porous materials that consist of metal-oxide clusters and organic compounds arranged in a chicken wire scaffolding structure. Tamer Yildirim and Michael Hartman from the National Institute for Standards and Technology’s Center for Neutron Research have found that MOF-5 can hold up to 10% of its weight in hydrogen at very cold temperatures (-200 degrees C). MOF-5 has a framework consisting of zinc-oxide clusters linked to benzene rings. Yildirim and Hartman observed that hydrogen molecules pack themselves into the lattice of oxygen and zinc atoms much like the way apples fill a bowl. They know they can store the hydrogen; the next step is finding a way to release the hydrogen.

So what about fuel cells you ask? Well, fuel cells run on oxygen and hydrogen. The oxygen is easy to get, but the hydrogen is not so easy. Most fuel cells use something called a reformer which turns hydrocarbons or alcohol fuels into hydrogen. So instead of carting around a giant tank of hydrogen, you’re making your own as you drive along. The problem is reformers generate heat and the hydrogen it produces is not so pure and lowers the efficiency of the fuel cell.

We know how to make hydrogen. We’re learning better ways for storing it and we know how to convert it to make energy. Now if we could just get all this combined together we could have one cool hydrogen-powered car.