Propene (or propylene) is an important chemical building block. It is usually produced as one product of steam cracking in the petrochemical industry. However, a rising propene demand and the increased use of shale gas in some applications has led to serious shortages in propene supply. Therefore, direct methods for the synthesis of propene that do not depend so heavily on trends in the petrochemical industry would be useful.
Jingguang G. Chen, Columbia University, New York, USA, and Brookhaven National Laboratory, Upton, NY, USA, and colleagues have studied such a propene synthesis, namely the direct dehydrogenation of propane using CO2 as an oxidant. The reaction could provide direct access to propene while consuming a greenhouse gas. The team used flow reactor studies to find suitable catalysts for the reaction and performed X-ray absorption spectroscopy measurements and density functional theory (DFT) calculations to study the reaction pathways.
The researchers found that bimetallic catalysts supported on ceria (CeO2) are promising for the reaction. A catalyst based on non-precious metals (Fe3Ni) was found to be selective for the production of propene. Similar catalysts based on nickel and platinum (Ni3Pt), in contrast, can produce useful syngas (a mixture of CO and H2) under the same conditions. According to the DFT calculations, this difference is due to the Fe3Ni catalyst favoring the breaking of C–H bonds, while the platinum-covered surface of the Ni3Pt catalyst favors C–C bond breaking.
- Combining CO2 reduction with propane oxidative dehydrogenation over bimetallic catalysts,
Elaine Gomez, Shyam Kattel, Binhang Yan, Siyu Yao, Ping Liu, Jingguang G. Chen,
Nat. Commun. 2018.