Advertisement
Advertise Here
-
November 1, 2010 - Volume 88, Number 44
- p. 9
- DOI:10.1021/CEN102810151609
[an error occurred while processing this directive]
Forensic Chemistry: A new method could increase the number of explosives detected by airport screeners.
Trade: U.S. companies complain of market dumping by China.
Layoffs follow similar moves by Amgen, AstraZeneca.
Environment: Ban to halt export of hazardous waste to developing world.
Penrose (Parney) Albright will direct DOE national lab.
Toxic Exposure: Mercury isotopes in human hair illuminate dietary and industrial sources.
Cancer Biochemistry: Mass spectrometry follows the metabolism of very long fatty acids in cancer cells.
By combining experimental and computational methods to examine an amine-functionalized metal-organic-framework (MOF) compound, researchers in Canada have identified the chemical nature of carbon dioxide-binding sites in that porous crystalline material (Science 2010, 330, 650). The study reveals molecular-level details of nitrogen-CO2 interactions, which are central to commercial CO2-scrubbing systems. The findings could lead to advances in carbon-capture technology.
Carbon cleanup in industrial settings today is often carried out by flowing flue gases through a column containing an aqueous solution of amine compounds such as monoethanolamine to selectively extract CO2 from the exhaust stream. The CO2-enriched solution is then typically heated to above 100 °C to remove the CO2 and regenerate the amine solution.
Technology based on those processes is well established. Nevertheless, various shortcomings, such as the corrosive nature of the solutions and the high energy input required to regenerate them, leave room for improvement.
Solid adsorbents might offer viable alternatives, especially because some MOF compounds exhibit the capacity to take up exceptionally high quantities of CO2. That feature has motivated researchers to synthesize large numbers of these compounds, including ones with amine moieties, in hopes of pushing CO2 uptake even higher.
In the new work, a team led by chemists Ramanathan Vaidhyanathan and George K. H. Shimizu of the University of Calgary and Tom K. Woo of the University of Ottawa used crystallography and computational techniques to sort out subtle details of CO2 binding in an amine-functionalized zinc-based triazole oxalate compound. Among other findings, the group determined the geometry of the amine-CO2-binding site in the MOF. The researchers found that cooperative binding of CO2 in the form of dimers and suitable pore size are collectively responsible for the material’s high uptake of the gas.
“This study reveals for the first time the specific interactions that hold CO2 in the pores of amine-functionalized MOFs,” says Omar M. Yaghi of the University of California, Los Angeles. “This is a significant step toward understanding what makes for a good CO2-capture material.”
ACS is the leading employment source for recruiting scientific professionals. ACS Careers and C&EN Classifieds provide employers direct access to scientific talent both in print and online. Jobseekers | Employers
Join more than 161,000 professionals in the chemical sciences world-wide, as a member of the American Chemical Society.
» Join Now!