|
Model
for Ceria Oxide System. Ceria
atoms are yellow, oxygen atoms
are blue, and the active oxygen
at the defects are purple. |
Catalysts, which accelerate chemical
reactions, are valuable in many industries,
from fuels to pharmaceuticals. Long-term
research by government and academic
scientists supported by the Office
of Science has led to new understanding
of catalytic phenomena, in particular
the relationship between chemical
structure and reactivity. For example,
early work established two classes
of heterogenous catalysts (which function
by adsorbing molecules), based on
whether chemical reactivity is, or
is not, sensitive to surface structure.
These studies showed that catalytic
reactions once thought to be structurally
insensitive actually took place on
a dynamic surface. Research on the
reactivity of hydrogen with catalystsan
issue in the world's largest-scale
industrial processes, such as sulfur
removal from crude oil-disproved the
widely held belief that hydrogen molecules
must dissociate into two atoms before
undergoing reactions, and challenged
the accepted notion that surface-bound
(as opposed to embedded) hydrogen
was the only reactive form. Other
discoveries concerned the chemical
behavior of organometallic complexes
(combinations of organic and metallic
species) that are used, for example,
in plastics manufacturing.
Scientific Impact:
Research on structure-reactivity relationships
has increased understanding of both
natural and synthetic processes. The
discovery of nonclassical binding
of molecular hydrogen created a new
field of study that may overcome some
of chemistry's greatest challenges,
such as conversion of natural gas
to more usable liquid fuels (methanol
or gasoline).
Social Impact: A
modern society's standard of living
can be measured by its accomplishments
in catalysis, because every manufacturing
process and energy-generating technique
starts with catalysis. Catalysts first
introduced by investigators supported
by the Office of Science revolutionized
a process used to make about 100 billion
pounds of plastics per year worldwide;
this work is leading to catalysts
that produce superior plastics with
new properties.
Reference: C.E.
Tripa and J.T. Yates, Jr. Nature,
398 (1999) 591.
URL:
http://www.sc.doe.gov/production/bes/chm/Programs/programs.html
Technical Contact:
Don Freeburn, Office of Basic Energy
Sciences, 301-903-3156
Press Contact: Jeff
Sherwood, DOE Office of Public Affairs,
202-586-5806
SC-Funding Office:
Office of Basic Energy Sciences |