The behavior of individual hydrogen atoms on titanium oxide surface reveals intriguing details about a popular oxide catalyst
Scanning tunneling images (left, from top) show atoms on the titanium oxide catalyst surface before and after water adsorption and after hydrogen hopping. Light blue oxygen atoms appear as depressions, red titanium atoms as protrusions. Yellow indicates hydrogen atoms from the water molecule. On the right is a model showing water splitting.
Researchers at Pacific Northwest
National Laboratory and the University
of Texas at Austin discovered that a single
hydrogen atom just canít keep still after it
splits from a water molecule on the surface
of the catalyst rutile titanium oxide. The
hydrogen atom hopscotches across the
oxygen atoms that stud the surface of the
catalyst, while the hydrogen on what is left
from water remains fixed, suggesting that
the electronic structure of this popular
catalyst is not entirely as it seems.
By understanding how waterís
atoms behave on the catalyst
surface, scientists and engineers
may be able to develop technologies
that use abundant, free sunlight to
split water to generate hydrogen gas,
a possible alternative fuel for
everything from heating homes
to powering automobiles.
The researchers plan to study
the titanium oxide material at higher
temperatures to see how fast the hydrogen
atoms move. They are also working on
developing a detailed understanding of
the underlying mechanisms and involved
The Department of Energy's Office of Science is the single largest supporter of basic research in the physical sciences in the United States and is working to address some of the most pressing challenges of our time.