Print Email Facebook Twitter Revealing Active Sites and Reaction Pathways in Methane Non-Oxidative Coupling over Iron-Containing Zeolites Title Revealing Active Sites and Reaction Pathways in Methane Non-Oxidative Coupling over Iron-Containing Zeolites Author Zhang, Hao (Eindhoven University of Technology) Bolshakov, Aleksei (Eindhoven University of Technology) Meena, Raghavendra (Wageningen University & Research) Garcia, Gustavo A. (L'Orme les Merisiers Saint-Aubin) Dugulan, A.I. (TU Delft RST/Fundamental Aspects of Materials and Energy; TU Delft RID/TS/Instrumenten groep) Parastaev, Alexander (Eindhoven University of Technology) Li, Guanna (Wageningen University & Research) Hensen, Emiel J.M. (Eindhoven University of Technology) Kosinov, Nikolay (Eindhoven University of Technology) Date 2023 Abstract Non-oxidative coupling of methane is a promising route to obtain ethylene directly from natural gas. We synthesized siliceous [Fe]zeolites with MFI and CHA topologies and found that they display high selectivity (>90 % for MFI and >99 % for CHA) to ethylene and ethane among gas-phase products. Deactivated [Fe]zeolites can be regenerated by burning coke in air. In situ X-ray absorption spectroscopy demonstrates that the isolated Fe3+ centers in zeolite framework of fresh catalysts are reduced during the reaction to the active sites, including Fe2+ species and Fe (oxy)carbides dispersed in zeolite pores. Photoelectron photoion coincidence spectroscopy results show that methyl radicals are the reaction intermediates formed upon methane activation. Ethane is formed by methyl radical coupling, followed by its dehydrogenation to ethylene. Based on the observation of intermediates including allene, vinylacetylene, 1,3-butadiene, 2-butyne, and cyclopentadiene over [Fe]MFI, a reaction network is proposed leading to polyaromatic species. Such reaction intermediates are not observed over the small-pore [Fe]CHA, where ethylene and ethane are the only gas-phase products. Subject C−C CouplingIronMethaneNon-OxidativeZeolites To reference this document use: http://resolver.tudelft.nl/uuid:2a798bd8-0c01-4cbb-89c3-6536eb83d433 DOI https://doi.org/10.1002/anie.202306196 ISSN 1433-7851 Source Angewandte Chemie (International Edition), 62 (32) Part of collection Institutional Repository Document type journal article Rights © 2023 Hao Zhang, Aleksei Bolshakov, Raghavendra Meena, Gustavo A. Garcia, A.I. Dugulan, Alexander Parastaev, Guanna Li, Emiel J.M. Hensen, Nikolay Kosinov Files PDF Angew_Chem_Int_Ed_2023_Zh ... over_1.pdf 7.91 MB Close viewer /islandora/object/uuid:2a798bd8-0c01-4cbb-89c3-6536eb83d433/datastream/OBJ/view