Last month, scientists converted greenhouse gas into fuel––by mistake.
A team of nanotechnology researchers at the Department of Energy’s Oak Ridge National Laboratory in Oak Ridge, Tennessee, were trying to grow catalysts on graphene, a layer of pure carbon, when they unexpectedly found a process that can turn carbon dioxide into pure ethanol.
In chemistry, a catalyst is a substance that increases the rate of a chemical reaction on its own, without being consumed or otherwise altered.
“We discovered somewhat by accident that this material worked,” said team member Adam Rondinone of the process in a press release. “We were trying to study the first step of a proposed reaction when we realized that the catalyst was doing the entire reaction on its own.”
When equipment limitations prevented the team from making graphene, they realized instead they could manufacture the catalysts in a tapered shape, much like a lightning rod or a spike.
“[It] concentrates the electric field right there at the tip,” explains Rondinone in an Oak Ridge Laboratory YouTube video.
The scientists then ran 1.2 volts of electricity—less power than an AA battery––through the copper-coated catalysts, which stand about 50 nanometers high, or approximately 1 millionth of a millimeter, and are submerged in water.
When the researchers bubbled CO2 through the water, they assumed based on prior results that the catalysts would convert the gas into methanol, but were stunned to find the electrochemical process instead produced straight ethanol alcohol.
“We’re taking carbon dioxide, a waste product of combustion, and we’re pushing that combustion reaction backwards with very high selectivity to a useful fuel,” said Rondinone. “Ethanol was a surprise––it’s extremely difficult to go straight from carbon dioxide to ethanol with a single catalyst.”
Ethanol, itself a viable fuel source, is currently added to gasoline worldwide and can be used in the current vehicle fleet. (In the U.S., gasoline contains 10 percent ethanol; in other countries the percentage is even higher. Gasoline in Brazil, for example,
Kat Merck is a freelance writer and editor based in Portland, Oregon. An amateur naturalist who studied forestry and natural resources at Cal Poly State University in San Luis Obispo, she writes on a wide range of topics for local and national publications.