A German scientist, Gerhard Ertl, has won the Nobel Prize in Chemistry for experiments showing how atoms and molecules react on solid surfaces—work that has laid the foundation for the entire field of surface chemistry.
Surface chemistry underlies many industrial processes, including the production of artificial fertilizers, electronic components, and renewable fuels. It is also critical to understanding basic processes such as why iron rusts and why the atmosphere's ozone layer is diminishing (some reactions that degrade ozone actually occur on the surface of ice crystals).
Mr. Ertl, who was born in 1936 and is a professor emeritus at the Fritz Haber Institute of the Max Planck Society, in Berlin, won the prize on his 71st birthday.
The Royal Swedish Academy of Sciences, which announced the award on Wednesday, cited Mr. Ertl for developing the experimental methods to study how atoms and molecules interreact on the surfaces of various substances. The research is particularly tricky because it involves taking atomic-scale measurements as atoms or molecules collide with a pure solid surface. The work typically is done in clean rooms—labs with filters and other devices to sterilize the work area and minimize contamination—and uses instruments like vacuum chambers and electron microscopes.
Some of Mr. Ertl's earliest work focused on the behavior of hydrogen gas on metal surfaces. He then shifted his attention to understanding the Haber-Bosch process, in which nitrogen in the air is combined with hydrogen on the surface of grains of iron to produce ammonia, which is then added to fertilizer. Fritz Haber won the Nobel Prize in Chemistry in 1918 for developing the process, which is the most difficult aspect of producing fertilizer. But Mr. Ertl's technique revealed how the reaction actually works at the molecular level.
"The announcement didn't surprise me," said Robert Tilton, a professor of chemical engineering and biomedical engineering at Carnegie Mellon University. "I've known about him since my undergraduate days. He's a pioneer in understanding how metal surfaces increase the rate of chemical reactions."
Metallic Collisions
The experimental techniques that Mr. Ertl developed have enabled scientists to tease apart chemical reactions and understand which bonds are broken first as molecules collide with metal surfaces, and how other bonds are then formed.
The techniques reveal step-by-step snapshots of how chemicals react to form new compounds. The findings have been particularly useful in the oil-refining industry, where many chemical reactions proceed at rates that are too sluggish to be economically useful. Mr. Ertl's work showed how those reactions could be accelerated using the surfaces of highly reactive metals, said Mr. Tilton. "It was his insights that led to making oil refining really efficient."
Mr. Ertl's research provided insights into two chemical reactions that have had a huge effect both economically and environmentally, said Bruce Bursten, president-elect of the American Chemical Society and dean of the College of Arts and Sciences at the University of Tennessee at Knoxville.
The prize winner figured out how molecules of nitrogen and hydrogen mingle on an iron surface to yield ammonia—a key ingredient in artificial fertilizers. He also revealed exactly how toxic carbon-monoxide gas is converted into less-harmful carbon dioxide on the metal surface of a car's catalytic converter.
Nobel Boom for Europeans
This year's Nobel laureates in science reflect a philosophical change on the Nobel-awarding committees' criteria, said Mr. Bursten. "The scientist's work must not only be fundamental but have an impact on humanity." Monday's medicine prize went to scientists who had developed genetic techniques to study human diseases in mice. Tuesday's physics prize went to researchers whose work made possible advances in the hard drives of modern computers.
This year's prizes in medicine, physics, and chemistry were also a boon to European science. Even though a couple of the winners work at American universities, most of the prize-winning research was done in Europe, and all but one of the winners were educated there.
One American scientist who has done work closely related to Mr. Ertl's is Gabor Somorjai, a professor of chemistry at the University of California at Berkeley. He also studies surface-chemistry phenomena like adhesion, lubrication, and catalysis. He shared the prestigious Wolf Prize with Mr. Ertl in 1998, and he is the 2008 recipient of the American Chemical Society's highest honor, the Priestley Medal.
The Wolf Prize is often considered a precursor to a Nobel, said Mr. Bursten. "It would not have surprised me if he had shared the award." It's always hard to say what to expect from the Nobel committee, he added.
