Revealing Active Sites and Reaction Pathways in Methane Non‐Oxidative Coupling over Iron‐Containing Zeolites

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 found that they display high selectivity (>90 % for >99 CHA) ethane among gas-phase products. Deactivated can be regenerated by burning coke in air. In situ X-ray absorption spectroscopy demonstrates the isolated Fe3+ centers zeolite framework fresh catalysts are reduced during reaction active sites, including Fe2+ species Fe (oxy)carbides dispersed pores. Photoelectron photoion coincidence results show methyl radicals intermediates formed upon activation. Ethane radical coupling, followed its dehydrogenation ethylene. Based on observation allene, vinylacetylene, 1,3-butadiene, 2-butyne, cyclopentadiene over [Fe]MFI, network proposed leading polyaromatic species. Such not observed small-pore [Fe]CHA, where only