In a well-known fairy tale, Rumpelstiltskin used magic to weave straw into gold. Today, scientists are reversing that formula using gold to turn straw (and other forms of biomass) into today's global currency: energy.
The magic involves a special nanocatalyst, in which minute particles of gold dot the surface of titanium-oxide. The forces that emerge from the combination of these two materials are strong enough to breaks the O-O bond of oxygen molecules and the C-O bond of acetic acid, a byproduct of biomass conversion that, when combined with hydrogen, forms ethanol, an important precursor for fuel.
Because of its ability to split strongly bonded molecules, the gold titanium-oxide nanocatalyst is becoming a leading candidate for industrial applications that use biomass or fuel cells to create clean energy.
"Metal nanoparticles supported on oxide surface are very popular because they have high activity towards a variety of reactions, especially oxidation reactions," said Wenjie Tang, a research associate in the department of chemical engineering at the University of Virginia and a member of the Neurock group there. "People know they're active, but how they work and the real mechanism of their active sites was not quite understood."
Combining computer simulations and laboratory experiments, Tang and others from the University of Virginia discovered a reaction site on the perimeter of the gold-titanium complex that does much of the work of catalysis.
"Previously, researchers thought it might be only the gold that was active in the reaction; they didn't think the oxide surface had any influence," Tang said. "But recently we realized that the oxides play an important role in modifying the metals above them. They create this a special site at the perimeter which is really the important site for the reaction."
The researchers initial findings were reported in the August 2011 edition of Science. Further res
|Contact: Faith Singer-Villalobos|
University of Texas at Austin, Texas Advanced Computing Center