Active sites of the methane dehydroaromatization catalyst W-ZSM-5: An HRTEM study

Nonoxidative methane conversion into aromatic hydrocarbons on a zeolite modified with nanosized tungsten powder has been studied. The highest methane conversion and the maximum yield of aromatic hydrocarbons are attained on the catalyst containing 8.0 wt % W. The nature and the distribution of the active phases in the W-containing zeolite were investigated by high resolution transmission electron microscopy and energy dispersive x-ray spectroscopy. The deactivation of the W-HZSM-5 catalyst was studied at different stages of methane conversion. The distribution of coke deposits on the surface of the W-HZSM-5 catalyst was determined.