Hydrogen has yet to live up to its full promise as an emission free way to power cars and other vehicles, partly because it is extremely temperamental in terms of handling. Now scientists at Brookhaven National Laboratory have found a way to make the cantankerous beast behave like ordinary gasoline or other liquid petroleum-based fuels, paving the way for low cost hydrogen fuel storage and transportation using infrastructure that already exists.
A kinder, gentler hydrogen fuel
Building on earlier research into the behavior of hydrogen combined with carbon dioxide, Brookhaven’s goal was to produce a solution of formic acid which, as a liquid, could be stored and transported practically like gasoline. That sounds easy enough, but the trick is to find an efficient catalyst to create the solution and get it to reform into hydrogen and carbon dioxide gas when desired. The team settled on a catalyst based on iridium. As explained by Brookhaven’s research team leader Etsuko Fujita:
“This is not the first catalyst capable of carrying out this reaction, but it is the first to work at room temperature, in an aqueous (water) solution, under atmospheric pressure — and that is capable of running the reaction in forward or reverse directions depending on the acidity of the solution.”
Many hands in the hydrogen broth
Brookhaven was far from the only lab involved in the research. Scientists from Baruch College and the U.S.-Japan Collaboration on Clean Energy program (which includes Japan’s National Institute of advanced Industrial Science and Technology) had a hand in determining exactly how the reaction creates formic acid, and the Scripps Research Institute contributed a synthetic ligand that boosted the efficiency of the catalyst.
Advantages of the new catalyst
Conventional hydrogen storage involves manipulating temperature and pressure, which requires energy. So far, tests have shown that the new catalyst can accomplish the same thing under ambient room temperature and pressure. As for releasing hydrogen from the solution, “one can simply flip the ‘pH switch’ on the catalyst,” according to chemist James Muckerman.
The next steps for the research involve fine tuning the catalyst to find the most cost effective storage process.
More progress on cheap hydrogen fuel
As for manufacturing hydrogen, that is another energy intensive process that is being addressed with the help of federally funded research and other partners. Scientists at Lawrence Berkeley National Laboratory, for example, have been developing a solar powered process enhanced by titanium crystals. The famous “artificial leaf” from Daniel Nocera at MIT also uses solar energy, and researchers at Duke University are developing
Meanwhile, the Department of Energy is pushing ahead with fuel cell research and development through the National Renewable Energy Laboratory, and a major hydrogen fuel cell project in Hawaii is under way for the entire island of Oahu with the help of numerous partners including the U.S. Army.
Image: Courtesy of Brookhaven National Laboratory.
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Tina Casey specializes in military and corporate sustainability, advanced technology, emerging materials, biofuels, and water and wastewater issues. Tina’s articles are reposted frequently on Reuters, Scientific American, and many other sites. You can also follow her on Twitter @TinaMCasey and Google+.