It can take years for new research findings to move from the lab to commercial development – and that’s if they move at all. Recent work by a faculty member with the UH Cullen College of Engineering, though, has made the jump in a matter of weeks.
Jeffrey Rimer, assistant professor of chemical and biomolecular engineering, is working with petrochemical companies to commercialize his technique for creating more efficient catalysts for chemical reactions. Rimer published his first article on this technique in a recent issue of Angewandte Chemie International Edition, which is one of the highest impact journals in general chemistry research. This work was featured on the back cover of the April 2nd issue.
This method involves a class of materials known as zeolites. As catalysts, zeolites are used in the petroleum and chemicals industries to produce many different products.
Zeolites are nanoporous materials that are able to perform this function thanks to the small channels that span their entire structure. Molecules enter the channels, react within the zeolite pores and then exit, transformed into something new.
As a rule of thumb, the thinner these channels, the better, said Rimer. In longer channels, residue from the reactions is more likely to build up in the pores, limiting zeolite efficiency. In addition, thinner channels increase the product yield.
“If a molecule enters the zeolite and reacts, you want the products to exit quickly to improve efficiency,” said Rimer. “If you have a zeolite with really long channels, the molecular flux is very low. An ideal catalyst is a thin crystal with high porous surface area, allowing molecules to enter, react, and then diffuse rapidly.”
So Rimer has developed – and recently won a full patent for – a method to produce ultra-thin zeolites. During the synthesis of commercial-grade zeolites, individual crystals grow through the attachment of growth units to sites on the zeolite surface. Rimer has discovered certain molecules that attach to specific zeolite surfaces and block growth sites, thereby tailoring the size and shape of zeolite crystals.
While the modified zeolites retain the same basic shape, through this process they are about 10-times thinner than unmodified zeolites, measuring as thin as 100 nanometers.
While Rimer hasn’t performed extensive testing on the zeolites he has modified, other ultra-thin zeolites are projected to have a lifetime four times longer than normal. Depending on the chemical reaction being considered, they could also offer dramatically increased efficiency.
One of the advantages of Rimer’s method for producing ultra-thin zeolites, though, is its practicality. While other methods rely on expensive molecules to control zeolite thickness, Rimer’s approach is far cheaper and easier to implement, making an effective business case for their use.
“The molecules used in our approach are commercially available and relatively inexpensive,” he said. “This is something that could be integrated into an existing process very easily, without requiring equipment upgrades or dramatic changes in operating conditions, so from an economic perspective, this could be very attractive for industry.”