Selective Coke Combustion by Oxygen Pulsing During Mo/ZSM-5-Catalyzed Methane Dehydroaromatization

Nikolay Kosinov; Ferdy J A G Coumans; Evgeny Uslamin; Freek Kapteijn; Emiel J M Hensen

doi:10.1002/anie.201609442

Selective Coke Combustion by Oxygen Pulsing During Mo/ZSM-5-Catalyzed Methane Dehydroaromatization

Angew Chem Int Ed Engl. 2016 Nov 21;55(48):15086-15090. doi: 10.1002/anie.201609442. Epub 2016 Oct 28.

Authors

Nikolay Kosinov¹, Ferdy J A G Coumans¹, Evgeny Uslamin¹, Freek Kapteijn², Emiel J M Hensen¹

Affiliations

¹ Laboratory of Inorganic Materials Chemistry, Eindhoven University of Technology, P.O. Box 513, 5600, MB, Eindhoven, The Netherlands), E-mail: E.J.M.
² Catalysis Engineering, ChemE, Delft University of Technology, van der Maasweg 9, 2629, HZ, Delft, The Netherlands.

Abstract

Non-oxidative methane dehydroaromatization is a promising reaction to directly convert natural gas into aromatic hydrocarbons and hydrogen. Commercialization of this technology is hampered by rapid catalyst deactivation because of coking. A novel approach is presented involving selective oxidation of coke during methane dehydroaromatization at 700 °C. Periodic pulsing of oxygen into the methane feed results in substantially higher cumulative product yield with synthesis gas; a H₂ /CO ratio close to two is the main side-product of coke combustion. Using ¹³ C isotope labeling of methane it is demonstrated that oxygen predominantly reacts with molybdenum carbide species. The resulting molybdenum oxides catalyze coke oxidation. Less than one-fifth of the available oxygen reacts with gaseous methane. Combined with periodic regeneration at 550 °C, this strategy is a significant step forward, towards a process for converting methane into liquid hydrocarbons.

Keywords: Mo/HZSM-5; arenes; catalyst deactivation; catalyst regeneration; methane dehydroaromatization.

Publication types

Research Support, Non-U.S. Gov't