Rice Researchers Say Tiny Cages Can Hold Super-Dense Hydrogen
by: Jack Williams, March 24, 2008 12:03:00 pm
For years, researchers have looked for ways to store hydrogen in a practical and cost-effective way for use in vehicles. It hasn't been easy for scientists like Rice University mechanical engineering and materials science professor Boris Yakobson.
"The difficulty with hydrogen is that it's a very volatile gas. It likes to be in gas form. It's very difficult to compress to sufficient density to be stored onboard a vehicle or an airplane someday. As a result, there is a pretty broad and diverse research effort nationwide and even worldwide in trying to find some storage options."
But Yakobson thinks he's closer than ever to proving tiny carbon cages, known as buckyballs, can store highly-dense volumes of hydrogen. The research is only theoretical at this point, but using calculations, Yakobson has found the super- strong carbon cages, even at larger sizes, can hold enough condensed hydrogen to make them viable as possible energy storage devices.
"To be safe, I can tell you from the graphs and plots which we included in this report, you can see that even if you go down to one-quarter of the failure limit, you still have pretty good density of hydrogen and good fraction between amount of stored hydrogen and the weight of the cage."
While Yakobson and his colleagues have determined the buckyballs are strong enough to hold condensed hydrogen, they haven't figured-out yet how to get the gas inside the tiny carbon cages. He says there might be several options.
"You can open cage wall, open hole there, and then you can close it again. It has been demonstrated. The question is of course which remains, can you do it at high pressure, because after you open it you have to put hydrogen inside and then doing second reaction may be difficult."
Another option Yakobson wants to try is to simply immerse the buckyballs in hydrogen and see if they somehow absorb the gas. His research appears on the cover of the American Chemical Society's journal Nano Letters this month.