Writing this week in the journal Science (June 27) University of Wisconsin-Madison chemical and biological engineers report the discovery of a nickel-tin catalyst that can replace the precious metal platinum in a new, environmentally sustainable, greenhouse-gas-neutral, low-temperature process for making hydrogen fuel from plants.
The new catalyst, together with a second innovation that purifies hydrogen for use in hydrogen fuel cells, offers new opportunities toward the transition of a world economy based on fossil fuels to one based on hydrogen produced from renewable resources.
James Dumesic, a professor of chemical and biological engineering, and graduate students George Huber and John Shabaker describe testing more than 300 materials to find a nickel-tin-aluminum combination that reacts with biomass-derived oxygenated hydrocarbons to produce hydrogen and carbon dioxide without producing large amounts of unwanted methane.
"Platinum is very effective but it's also very expensive," says Dumesic. "It's also problematic for large-scale power production because platinum is already in demand for use as anode and cathode materials in hydrogen fuel cells. We knew nickel was very active, but it allowed reaction to continue beyond hydrogen producing methane. We found that adding tin to what's known as a Raney-Nickel catalyst decreased the rate of methane formation without compromising the rate of hydrogen production."
Dumesic, research scientist Randy Cortright (now at Virent Energy Systems) and graduate student Rupali Davda first reported the catalytic reforming process for hydrogen production in the Aug. 29, 2002 issue of the journal Nature.
The simple, single-step process employs temperature, pressure and a catalyst to convert hydrocarbons such as glucose, the same energy source used by most plants and animals, into hydrogen, carb
Contact: James Dumesic
University of Wisconsin-Madison