Researchers have synthesized a new class of
aluminum-hydrogen compounds with a unique chemistry that
could lead to the development of more powerful solid rocket
fuel and may also, in time, be useful for hydrogen-powered
vehicles or other energy applications.
An article about this research, led by scientists at
the Johns Hopkins and Virginia Commonwealth universities,
is published in the Jan. 19 issue of the journal
Science. The team also included scientists at
University of Konstanz and University of Karlsruhe, both in
Through combined theoretical and experimental study,
the team created this new class of aluminum/hydrogen
molecules (called "hydrides") that are relatively stable
and are similar in structure to boranes, which are composed
of boron and hydrogen atoms. This relative stability may
hold the key to the compound's possible future uses in
rocket fuel, said team co-leader Kit Bowen, the E. Emmet
Reid Professor in the departments of
Science at Johns Hopkins.
"It's always tough to predict how things will play out
in the future, but our research finding is interesting
enough for me to be willing to say that this synthesis may
have the potential for some possibly very useful future
applications, including the development of solid rocket
fuel with more thrust," Bowen said.
Most solid rocket fuels already rely on aluminum as a
co-fuel, but the compounds synthesized by the research team
"might turn out to be more efficient," Bowen said.
"But that remains to be seen," he said. "These
complexes are a new class of thing that, because of their
various properties, can at this point only be imagined to
have uses in propulsion or even in the forecasted hydrogen
Today's so-called "petroleum economy" relies heavily
on fossil fuels for energy. In a "hydrogen economy,"
however, electricity to power vehicles and for the power
grid could be produced with much cleaner technologies using
hydrogen, the most abundant element in the universe, as a
fuel. Storing this fuel, however, presents tremendous
challenges, including finding a solid that efficiently
"soaks up and holds" hydrogen and then releases it on
"There are many bridges to cross," Bowen said.
"Perhaps it's best to think of the science we are doing
with these new compounds as being like inventing new words.
From those come sentences, paragraphs, chapters, whole
books and even, eventually, Shakespeare. Small things can
be the building blocks of larger ones down the line."
Team co-leader Puru Jena, distinguished professor of
physics at VCU, said that developing new materials and
compounds that meet some of the current technological
problems in energy-related fields is one of the objectives
of this kind of collaborative research.
"Our work has demonstrated that a synergy between
experiment and theory can go a long way in meeting these
challenges, particularly in developing novel nano-materials
for storing and releasing hydrogen as well as for
high-energetic materials applications," Jena said.
The experimental work for this project was conducted
by Bowen and his graduate students, X. Li, A. Grubisic and
S.T. Stokes, in the Chemistry Department at Johns Hopkins;
and by Gerd Gantefor and his graduate student, J. Cordes,
from the Department of Physics at Konstanz University. The
theoretical investigations were conducted by Jena and
Boggavarapu Kiran, along with M. Willis, a graduate student
in the Physics Department at VCU. Hansgeorg Schnockel and
his graduate student, R. Burgert, in the Institute of
Inorganic Chemistry at the University of Karlsruhe, also
This research was funded by the U. S. Air Force Office
of Scientific Research (which supports Bowen), the U. S.
Department of Energy (which supports Jena) and the Deutsche
Forschungsgemeinschaft (which supports Gantefor and