Carbonaceous Species Identified in Cluster-Mediated Methane Dehydrogenation
Catalytic activation of methane could allow for a more energy-efficient utilization of natural gas as major feedstock for higher-value hydrocarbon chemicals. The first step in this activation by catalyst material M is often the formation of an MCH2 carbene or HMCH hydrido carbyne intermediate.
A team of researchers from FELIX, the Technical University Munich and the Georgia Institute of Technology reacted methane with a tantalum cluster catalyst model system and revealed the formation of a third class of products, H2MC dihydride carbides, a product long deemed unfavorable to form.
The species found may be a precursor for unwanted coke formation, but could also be beneficial for the formation of value-added chemicals in still to be determined subsequent reaction steps. The results will further aid in the interpretation of operando measurements of catalytic reactions under realistic chemical process conditions.
In the study, the team used the FELICE free-electron laser to characterize the structure of the formed reaction product with IR spectroscopy. The results are published in Angewandte Chemie.
When methane reacts with a tantalum cluster (cyan), the methane gets ripped apart to form a departing hydrogen molecule. The remaining C and H atoms bind individually to the cluster.
Carbide Dihydrides: Carbonaceous Species Identified in Ta4+-Mediated Methane Dehydrogenation , Jozef Lengyel, Nikita Levin, Frank J. Wensink,Olga V. Lushchikova, Robert N. Barnett,Uzi Landman,Ueli Heiz,Joost M. Bakker and Martin Tschurl, Angew.Chem.Int.Ed. 10, 1002 (2020)