LSU professor takes on research of hydroformylation catalysts
Elaine Tagge | September 15, 2021
Baton Rouge, LA- In the industry of commercial aldehydes, affordable but effective catalysts are imperative for efficient production. An aldehyde is a compound most commonly used as a precursor to various commodities, such as in the creation of polymeric materials and various plastics. It is the product of a reaction known as hydroformylation, a chemical process which requires a transition metal catalyst.
Currently, cobalt and rhodium-based catalysts are the two most widespread types for commercial hydroformylation. Assistant Professor Matthew Chambers, a synthetic chemist at LSU whose research focuses on the process of aldehyde formation, explains, “There are pros and cons to each type of catalyst. The rhodium systems are much more active than the cobalt, and can operate at more desirable conditions. However, the metal itself is substantially more expensive. Cobalt catalysts are traditionally less active and require harsher conditions, and the higher temperatures and pressures demand much more expensive infrastructure to safely create and support these reaction conditions.”
Chambers now works in collaboration with Professor Emeritus George Stanley, who spearheaded the investigation of aldehyde formation in the Chemistry Department over the course of several decades. Stanley and his student researchers discovered the potential for a dream catalyst which utilized a specific cobalt platform that was found to maintain the heightened activity of a rhodium system.
During the hydroformylation process, a transition metal catalyst is bonded with carbon monoxide. These bonds are established through a trade of electrons, but the traditionally neutral catalysts often sacrifice too much of their electron density through the exchange. This can hinder or halt the catalysis process by creating interactions that are too stable.
It was found that this dream catalyst has a catatonic charge, which helps to allow the cobalt center to better retain its electron density while bonding with carbon monoxide and other substrates. This fundamental change in the way that a cobalt-based material interacts with carbon monoxide during catalysis is cited as a key reason for its high levels of activity in hydroformylation.
After Stanley retired, the torch was passed to Chambers and his student researchers, who have since initiated a project to further develop the systems of the dream catalyst. Their work was recently funded by a Board of Regents grant, which has allowed them to experiment with ligand modifications, metal variations, and mechanistic studies.
“This project is unique in that my research team has not been actively working on it prior to the grant being funded.” Chambers explains, “Since the initial discovery by Dr. Stanley and his students was so groundbreaking, there was in immense interest from industrial collaborators to continue this work… I’m very thankful for this arrangement since it’s certainly not common in chemistry fields but provides the students in my group an amazing opportunity to gain experience in such an exciting and applicable area of catalysis.”
A major component of hydroformylation research going forward will be the optimization of pre-catalysts, which are materials that generate the active catalyst after insertion into a reactor. “The work on this project is exactly what drew me to experimental chemistry in the first place. The beautiful part about chemistry is that we can go into a lab and make new molecules with whatever features we can dream of!” Chambers asserts, “The only thing limiting this work is the creativity of the researchers. We should have some exciting things on the horizon!”
Assistant Professor Chambers began his research career as an undergraduate in the laboratory of Dr. Pete Wolczanski at Cornell University, where he received his bachelor’s degree with honors. He continued to MIT for his Ph.D. in Inorganic Chemistry, which he received while working for Dan Nocera. He later worked as a postdoctoral researcher at the Collège de France with Marc Fontecave, and at UNC Chapel Hill with Alex Miller. To learn more about his work at LSU, visit his page on the Chemistry Department website. For detailed information about hydroformylation, a publication written by Dr. Stanley can be found in this College of Science article.