A key advance, newly reported by chemists from Brown and Yale Universities, could lead to a cheaper and more sustainable way to make acrylate, an important commodity chemical used to make materials from polyester fabrics to diapers.
Chemical companies churn out billions of tons of acrylate each year, usually by heating propylene, a compound derived from crude oil. “What we’re interested in is enhancing both the economics and the sustainability of how acrylate is made,” said Wesley Bernskoetter, assistant professor of chemistry at Brown, who led the research. “Right now, everything that goes into making it is from relatively expensive, nonrenewable carbon sources.”
Since the 1980s researchers have been looking into the possibility of making acrylate by combining carbon dioxide with a gas called ethylene in the presence of nickel and other metal catalysts. CO2 is essentially free and something the planet currently has in overabundance. Ethylene is cheaper than propylene and can be made from plant biomass.
There has been a persistent obstacle to the approach, however. Instead of forming the acrylate molecule, CO2 and ethylene tend to form a precursor molecule with a five-membered ring made of oxygen, nickel, and three carbon atoms. In order to finish the conversion to acrylate, that ring needs to be cracked open to allow the formation of a carbon-carbon double bond, a process called elimination.
That step had proved elusive. But the research by Bernskoetter and his colleagues, published in the journal Organometallics, shows that a class of chemicals called Lewis acids can easily break open that five-membered ring, allowing the molecule to eliminate and form acrylate.
Lewis acids are basically electron acceptors. In this case, the acid steals away electrons that make up the bond between nickel and oxygen in the ring. That weakens the bond and opens the ring.
“We thought that if we could find a way to cut the ring chemically, then we would be able to eliminate very quickly and form acrylate,” Bernskoetter said. “And that turns out to be true.”
He calls the finding an “enabling technology” that could eventually be incorporated in a full catalytic process for making acrylate on a mass scale. “We can now basically do all the steps required,” he said.
From here, the team needs to tweak the strength of the Lewis acid used. To prove the concept, they used the strongest acid that was easily available, one derived from boron. But that acid is too strong to use in a repeatable catalytic process because it bonds too strongly to the acrylate product to allow additional reactions with the nickel catalyst.
“In developing and testing the idea, we hit it with the biggest hammer we could,” Bernskoetter said. “So what we have to do now is dial back and find one that makes it more practical.”
There’s quite a spectrum of Lewis acid strengths, so Bernskoetter is confident that there’s one that will work. “We think it’s possible,” he said. “Organic chemists do this kind of reaction with Lewis acids all the time.”
The ongoing research is part of a collaboration between Brown and Yale supported by the National Science Foundation’s Centers for Chemical Innovation program. The work is aimed at activating CO2 for use in making all kinds of commodity chemicals, and acrylate is a good place to start.
“It’s around a $2 billion-a-year industry,” Bernskoetter said. “If we can find a way to make acrylate more cheaply, we think the industry will be interested.”
Other authors on the paper were Dong Jin and Paul Willard of Brown and Nilay Hazari and Timothy Schmeier of Yale.
Editors: Brown University has a fiber link television studio available for domestic and international live and taped interviews, and maintains an ISDN line for radio interviews. For more information, call (401) 863-2476.
Kevin Stacey | EurekAlert!
New findings help to better calculate the oceans’ contribution to climate regulation
14.11.2018 | Jacobs University Bremen gGmbH
How algae and carbon fibers could sustainably reduce the athmospheric carbon dioxide concentration
14.11.2018 | Technische Universität München
Biochips have been developed at TU Wien (Vienna), on which tissue can be produced and examined. This allows supplying the tissue with different substances in a very controlled way.
Cultivating human cells in the Petri dish is not a big challenge today. Producing artificial tissue, however, permeated by fine blood vessels, is a much more...
Faster and secure data communication: This is the goal of a new joint project involving physicists from the University of Würzburg. The German Federal Ministry of Education and Research funds the project with 14.8 million euro.
In our digital world data security and secure communication are becoming more and more important. Quantum communication is a promising approach to achieve...
On Saturday, 10 November 2018, the research icebreaker Polarstern will leave its homeport of Bremerhaven, bound for Cape Town, South Africa.
When choosing materials to make something, trade-offs need to be made between a host of properties, such as thickness, stiffness and weight. Depending on the application in question, finding just the right balance is the difference between success and failure
Now, a team of Penn Engineers has demonstrated a new material they call "nanocardboard," an ultrathin equivalent of corrugated paper cardboard. A square...
Physicists at ETH Zurich demonstrate how errors that occur during the manipulation of quantum system can be monitored and corrected on the fly
The field of quantum computation has seen tremendous progress in recent years. Bit by bit, quantum devices start to challenge conventional computers, at least...
09.11.2018 | Event News
06.11.2018 | Event News
23.10.2018 | Event News
14.11.2018 | Materials Sciences
14.11.2018 | Health and Medicine
14.11.2018 | Life Sciences