In chemical reactions, water adds speed without heat

An international team of researchers has discovered how adding trace amounts of water can tremendously speed up chemical reactions-such as hydrogenation and hydrogenolysis-in 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. Through an interaction with hydrogen atoms (green), a water molecule (magenta and blue) moves rapidly across a metal oxide surface. This atomic-scale speed leads to more efficient chemical reactions. 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 molecules-to add hydrogen-and 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.