Gabor Somorjai, the father of modern surface chemistry
10 May 2002
By Robert Sanders, Media Relations
Berkeley
- To chemist Gabor Somorjai, the entire world is superficial,
literally. Everything of importance happens at surfaces. Skaters
glide to gold medals on a film of water floating on the ice
surface. Friction creates heat at the place where two surfaces
meet. Our lungs absorb oxygen at an interface between solid
tissue and liquid. In fact "the whole body is a walking
solid-liquid interface," he says.
Somorjai
brought the study of surfaces out of the realm of physics into
chemistry to study these interesting and important real-world
problems, and in the process revolutionized thinking about the
nature of chemical reactions. As the recognized father of modern
surface chemistry, his discoveries have explained many of the
mysteries of surface interactions and led to new and improved
methods of using surfaces to make useful products - high-octane
gasoline, plastic polymers, and ammonia-based fertilizer.
These
achievements led this week to his being awarded one of 15 new
National Medals of Science, the nation's highest scientific
honor given for a lifetime of innovative research.
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Gabor
Somorjai in his laboratory in 1982.
Saxon Donnelly/UC Berkeley photo
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"I'm
very grateful," said Somorjai, 67, who came to this country
at the age of 21 after the Hungarian Revolution in 1956 and
enrolled in graduate school at UC Berkeley. "In 45 years,
a lot has happened that was very constructive and positive,
and I am absolutely delighted and honored that the country appreciated
that and rewards me with this medal.
"The
University of California has been very good to me, too, and
I am just very happy that I could give back by creating new
science and educating new generations of scientists in the process."
Born
in Budapest, Somorjai was a fourth-year chemical engineering
student at the capital's Technical University when the revolution
against the Communist regime began - a revolt that was brutally
put down. A member of the defeated militia, Somorjai quickly
left Hungary and immigrated to the United States, enrolling
in graduate school at UC Berkeley in 1957, along with some 50
other students from Hungary. He received his PhD in 1960 in
chemistry and joined the research staff of IBM, in Yorktown
Heights, N.Y., where he worked until he returned to UC Berkeley
as an assistant professor in 1964.
With
the advent of new techniques, like low energy electron diffraction,
to study surfaces on the atomic scale, surface physics studies
took off in the 1950s and '60s, he said. But because these techniques
required high vacuum, studies were limited to surfaces - silicon
and semiconductors - that were important for their electrical
properties.
Somorjai
was interested in surfaces important for their chemical properties,
like platinum, the "father of all catalysts," which
for nearly two centuries has been used to catalyze reactions
such as the explosive conversion of hydrogen and oxygen to water.
"Chemists are much more tolerant of complexity, and I was
putting molecules on surfaces - organic molecules of all things
- and looking at structures of monolayers, and reconstructions
of surfaces that are chemically interesting," he said.
"Once we began moving in this direction, we picked up and
developed new instrumentation that allowed us to look at surfaces
and reactions on a molecular level."
One
of his major discoveries was that defects on surfaces, like
steps and kinks, are where catalytic activity takes place. These
defects break and make bonds between atoms, allowing, for example,
complex organic chemicals like naphtha to be rearranged into
chemicals, such as gasoline.
His
approach was to work with simple surfaces -single, uniform metal
crystals - and discover how chemical reactions occur on them,
then extrapolate his findings to more complex surfaces like
those used in industrial reactions. His findings help scientists
and engineers understand many surface features of broad technical
importance, such as adhesion, lubrication, friction, absorption
catalysis and other phenomena that depend on surface interactions.
Somorjai's
successes have shed light on several new areas of science, including
nanoscience - the study of materials comprised of mere thousands
of atoms - and the biological reactions of enzymes.
"What
has happened in the last 5-6 years is that surface chemistry
is moving into even more complicated materials and to studies
of the solid-liquid interface, which means biology," he
said. "You can look at biopolymers like your skin, your
arteries or heart valves."
Over
the past 10 years, he and physics professor Ron Shen have developed
a technique, sum frequency generation surface vibration spectroscopy,
to study surface reactions under real conditions, without the
need for placing the surface in a vacuum chamber.
"We
can look at the surface while it is reacting, and we find that
the molecules that are usually easy to detect are stagnant,
they don't do any chemistry. So suddenly we can distinguish
between the molecules that are transients and come off as products
and the molecules that are just spectators."
Somorjai
has picked up another instrument, the atomic force microscope,
to study surface reactions in the nano-realm. He sees many of
the same principles that govern reactions at larger surfaces,
such as the importance of mobility, the need for chemicals to
move around easily on a surface in order for reactions to occur.
"All
catalysts are nanoparticles - clusters of atoms that do all
the chemistry. The question is why? Why doesn't nature use different
particles? The reason is that, as you do chemistry, the surface
restructures continuously to adapt to the chemistry that occurs,
to optimize bonding. And the restructuring is much easier with
little clusters, where you have only a few number of nearest
neighbors to move, than with a big single crystal, where you
have too many neighbors and it's too difficult to weaken bonding.
So nature loves clusters to do chemistry."
His
renown has brought some fun projects his way. Before this winter's
Olympic games in Salt Lake City, those responsible for freezing
the ice at the skating rink called to ask his opinion about
various techniques to make faster ice. He explained, for example,
that bubbles in ice make it slushy, because they promote surface
melting and thus a thicker water layer. Removing the bubbles,
as they do by steaming the ice, keeps the surface water layer
thin and the ice faster.
"To
me, one important aspect is the technological importance of
what we did, but the other important part is the conceptual
understanding of how surfaces work," he said, noting that
there is still much to learn about why ice is slippery and concrete
is not.
Through
his research, Somorjai has educated a generation of leading
scientists. Out of the more than 110 PhD students and 150 postdoctoral
fellows he has mentored, 60 hold faculty positions, a fact of
which he is very proud.
"The
outstanding graduate students and postdoctoral fellows who come
to Berkeley tend to be very creative and do high quality research,"
he said.
Somorjai
is the author of more than 850 scientific papers and three textbooks
on surface chemistry and heterogeneous catalysis. Among his
many awards and honors are the Wolf Foundation Prize in chemistry,
and from the American Chemical Society, the Peter Debye Award
in Physical Chemistry and the Adamson Award in Surface Chemistry.
He
was elected to the National Academy of Sciences in 1979, and
the American Academy of Arts and Sciences in 1983. In April
of this year, he was named a University Professor by the UC
Board of Regents, elevating him to the ranks of about two dozen
academics attached not solely to one campus, but to the entire
10-campus UC system.
He
hopes to attend the June 13 ceremonies at the White House with
his wife Judith, his son John, his daughter Nicole, and their
families.
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