XSEDE Science Successes

« Back

XSEDE Resources Used to Discover a New Type of Organometallic Compounds

XSEDE Resources Used to Discover a New Type of Organometallic Compounds

New Catalytic Process Seen as More Energy-Efficient, Environmentally Friendly 

Selective oxidation plays a key role in the production of compounds widely used throughout the chemical industry. Now, according to a new study using advanced computational resources, these materials and other compounds, such as those used to make polyester resins, could undergo a new catalysis process that uses less energy and generates fewer by-products than current methods.

The findings, published online this month in Theoretical Chemistry Accounts by Thomas Manz, a chemical engineering professor at New Mexico State University (NMSU) in Las Cruces, NM, are significant because they can be applied to chemical compounds used widely throughout commercial industry. Manz, with his Ph.D. student, Bo Yang, used more than one million computational hours over a period of several years via allocations from the National Science Foundation's eXtreme Science and Engineering Discovery Environment (XSEDE) to produce a new class of selective oxidation catalysts.

"Molecular oxygen is the ideal oxidant, because it is present in air and can potentially produce selective oxidation without co-products," said Manz, who works in NMSU's Department of Chemical and Materials Engineering. "While some selective oxidation processes efficiently utilize molecular oxygen, other selective oxidation products still lack an efficient catalyst to produce them using molecular oxygen as the oxidant without co-reductant." 

Specifically, the study suggests that a novel solution-phase bidentate zirconium complex can efficiently mediate selective oxidation reactions directly with molecular oxygen, without the need for coreactants. While this month's Theoretical Chemistry Accounts paper focuses on ethylene epoxidation, Manz and Yang's most recent computations, to be published in a follow-up study, show that their new catalyst can also be used in a two-catalyst process to selectively oxidize propene to propylene oxide using molecular oxygen as the oxidant without co-reductant.

"These latest findings are significant because it is much more difficult to produce propylene oxide than ethylene oxide," according to Manz. Propylene oxide, which is used to make polyurethanes, polyester resins, and other compounds, is one of the world's major chemical products, with global production estimated at about 15 billion pounds per year.

"We believe this is one of the first examples to date of designing a brand new catalytic route and catalyst class from scratch using quantum chemistry calculations, and one that will reduce unwanted co-products that can be environmentally unfriendly," said Manz. "We also are convinced that this new route can result in substantial energy savings when compared with existing processes which use a co-reductant or require an oxidant other than molecular oxygen."

All of the Density Functional Theory calculations used by Manz and Yang to design the new catalysts and selective oxidation processes were provided by the XSEDE network. XSEDE resources used include the Comet and Trestles systems at the San Diego Supercomputer Center (SDSC) at the University of California, San Diego; the Stampede system at the Texas Advanced Computing Center (TACC), and the Steele cluster housed at Purdue University. 

"The advanced state of computational power is what paved the way to discovering this new class of organometallic compounds that catalyze selective oxidation reactions by passing through eta3-ozone intermediates," said Manz. "We thank XSEDE's technical support staff for their assistance, and are currently developing collaborations with experimental groups to synthesize and test these new catalysts and selective oxidation processes."

This research was conducted under XSEDE project grant TG-CTS100027.