George A. Olah Award in Hydrocarbon or Petroleum Chemistry

William Schulz

Sponsored by the George A. Olah Endowment

Bruce E. Koel "has had a major impact on hydrocarbon chemistry," says John L. Falconer, a professor of chemical and biological engineering at the University of Colorado. And his work "has had a major impact on others" as indicated by his large number of invited talks and a citation rate of approximately 24 citations per paper.

Koel's career began with a solid background in surface science. His papers are considered important contributions to the surface science literature.

Next, he began integrating surface science techniques into the study of fundamental surface chemical problems relevant to many important technologies including catalysis and electrochemistry. A principal contribution was his investigation of the chemistry and catalysis on well-defined bimetallic alloy surfaces.

Chemisorption and surface reactions of dozens of small molecules, hydrocarbons, and intermediates have now been studied under ultra-high-vacuum (UHV) conditions, where the powerful spectroscopic tools of modern surface science can be utilized. In addition, these studies are being correlated with measurements, in his lab, of the high-pressure catalytic hydrogenation of crotonaldehyde and cyclohexanone over these same surfaces.

Koel's work to discover, characterize, and utilize ordered surface alloys (intermetallic compounds) grown on single-crystal substrates has greatly improved the understanding of fundamental principles that underpin alloy chemistry and that can be used to interpret or predict their catalytic properties.

"His work comprises the most detailed and complete exploration of the chemistry on platinum-tin alloy surfaces," notes David W. Goodman, a professor of chemistry at Texas A&M University. "Other than a few studies on oxidation of PtSn alloys, there was only the early work of Sachtler's on H₂ and ethylene adsorption on polycrystalline material when Bruce began. His most important contributions have derived from chemisorption studies on these surface alloys, correlating surface structure with chemisorption properties."

In other studies tackling fuel-cell electrode chemistry, Koel has shown that PtSn alloys are remarkably weakly interacting with organic compounds given the oxophilicity of tin. Methanol, ethanol, water, and even nitromethane are reversibly adsorbed under UHV conditions.

His chemisorption studies have led to the discovery of novel catalytic processes occurring in UHV. The two most significant aspects of these studies are the utilization of ordered surface alloys to provide a clear probe of site requirements for adsorption and reactions, showing clearly the importance of the threefold hollow site to hydrocarbon reactions, and the discovery of the importance of a modifier precursor in controlling adsorption kinetics on chemically modified or bimetallic surfaces.

Koel, 51, received a bachelor's degree in chemistry in 1976 from Emporia State University, in Kansas, and a Ph.D. in chemistry from the University of Texas, Austin. He is the recipient of numerous awards and has trained 43 graduate students and 23 postdoctoral fellows.

The award address will be presented before the Division of Colloid & Surface Chemistry.