MADISON An international team of researchers has discovered how adding trace amounts of water can tremendously speed up chemical reactionssuch as hydrogenation and hydrogenolysisin which hydrogen is one of the reactants, or starting materials.
Led by Manos Mavrikakis, the Paul A. Elfers professor of chemical and biological engineering at the University of Wisconsin-Madison, and Flemming Besenbacher, a professor of physics and astronomy at the University of Aarhus, Denmark, the team published its findings in the May 18 issue of the journal Science.
Hydrogenation and hydrogenolysis reactions have huge applications in many key industrial sectors, including the petrochemical, pharmaceutical, food and agricultural industries. "In the petrochemical industry, for example, upgrading of oil to gasoline, and in making various biomass-derived products, you need to hydrogenate moleculesto add hydrogenand all this happens through catalytic transformations," says Mavrikakis, who is among the top-100 chemists of the 2000-10 decade, according to Thomson Reuters.
A chemical reaction transforms a set of molecules (the reactants) into another set of molecules (the products), and a catalyst is a substance that accelerates that chemical reaction, while not itself being consumed in the process.
In industrial applications, the speed of catalytic transformations is important, says Mavrikakis. "The rate at which the hydrogen atoms diffuse on the surfaces of the catalyst determines, to a large extent, the rate of the chemical reactionthe rate at which we produce the products we want to produce," he says.
While many researchers have observed that water can accelerate chemical reactions in which hydrogen is a reactant or a product, until now, they lacked a fundamental grasp of how that effect was taking place, says Mavrikakis. "Nobody had appreciated the importance of water, even at the parts per million level," he says.
|Contact: Manos Mavrikakis|
University of Wisconsin-Madison