Scientists find safer way to store hydrogen

Australian scientists have come up with a clever way of storing hydrogen that they feel could make it a viable portable fuel source.

Hydrogen is abundant: pass a current through water and you'll make some. Hydrogen-powered fuel cells have therefore been advanced as a potential replacement for the internal combustion engine and even batteries in portable electronics, with Apple holding a patent for Hydrogen batteries.

George W Bush was a fan of the gas: his FreedomCAR program threw a billion dollars at fuel cells among other petroleum-free alternatives. Hydrogen-powered vehicles are also real: an H-Car led the women’s marathon at the Sydney Olympics, way back in 2000, while BMW and Toyota remain keen on Hydrogen as a fuel.

But the fact remains that Hydrogen burns rather well (while it did not cause the Hindenburg's demise its Hydrogen nonetheless burned) and can under some circumstances react nastily with other substances at room temperature. As nobody wants their car to go up in smoke, or for the fuel in its tank to spontaneously become an acid, exploration of fuel cells’ potential has moved slowly as boffins try to figure out the larger problem of just how to build a supply chain around a substance rather more volatile than petroleum.

Enter the Australian team from the University of New South Wales, which has found that compound named sodium borohydride (that’s NaBH₄ for all you chemists out there) can absorb lots of hydrogen and then release it under what the researchers describe as “mild pressure conditions” of four mega pascals (4 MPa). That’s rather less than the rating of most scuba diving cylinders and presents a less tricky challenge than storing the gas as .. well ... a gas.

Dr Kondo-Francois Aguey-Zinsou, lead author of a paper on the subject published in ACS Nano, told ABC News NaBH₄ acts like a “sponge” for hydrogen, and can soak up so much of the stuff that a conventionally-sized fuel tank stuffed full of the compound would get close to the energy potential of the same volume of petroleum.

But the news isn’t all good: the NaBH₄ needs to be nano-engineered and stored in a nickel shell. Even then it only releases some of the stored hydrogen at 50 degrees Celsius and it’s only once the mercury hits 350 that the hydrogen really starts to flow.

The Center for Functional Nanomaterials at UNSW’s School of Chemical Engineering, where the work was conducted, intends to keep tinkering with NaBH₄ as it believes there is the potential for “ … major advancements in the design of effective hydrogen storage materials from pristine borohydrides.” ®