Hybrid porous
catalysts can be “grown” to capture and convert carbon dioxide to useful fuels,
in analogy to a
plant’s ability to turn carbon dioxide into biomass. Computer modeling showed
how to tune
catalytic functional groups embedded within a nano-porous solid to facilitate
fast
reaction rates for converting carbon dioxide and
hydrogen to valuable products. (Design: Jingyun Ye)
(December 8, 2015) Pitt study outlines framework for developing catalysts that
turn excess atmospheric CO2 into new source of liquid fuel.
A team of chemical engineers at the University
of Pittsburgh recently identified the two main factors for determining the
optimal catalyst for turning atmospheric CO2 into liquid fuel. The results of
the study, which appeared in the journal ACS Catalysis, will streamline the
search for an inexpensive yet highly effective new catalyst.
Imagine a power plant that takes the excess carbon dioxide
(CO2) put in the atmosphere by burning fossil fuels and converts it back into
fuel. Now imagine that power plant uses only a little water and the energy in
sunlight to operate. The power plant wouldn’t burn fossil fuels and would
actually reduce the amount of CO2 in the atmosphere during the manufacturing
process. For millions of years, actual plants have been using water, sunlight,
and CO2 to create sugars that allow them to grow. Scientists around the globe
are now adopting their energy-producing behavior.
“We’re trying to speed up the natural carbon cycle and make
it more efficient,” said Karl Johnson, the William Kepler Whiteford Professor
in the Department of Chemical & Petroleum Engineering at the University of
Pittsburgh and principal investigator of the study. “You don’t have to waste energy
on all the extra baggage it takes to grow plants, and the result is a man-made
carbon cycle that produces liquid fuel.”
There’s one catch. CO2 is a very stable molecule, and
enormous amounts of energy are required to get it to react. One common way to
make use of excess CO2 involves removing an oxygen atom and combining the
remaining CO with H2 to create methanol. However, during this process parts of
the conversion reactor need to heat as high as 1000 degrees Celsius, which can
be difficult to sustain, especially when the only energy source is the sun.