Non-oxidative direct conversion of methane: Improved reactivity via linkage with dehydroaromatization

Abstract

The direct conversion of methane without an oxidant is an attractive approach to increase carbon efficiency. However, the reaction must be engineered appropriately. Herein, we propose a methane to olefins, aromatics, and hydrogen (MTOAH) system in which methane activation is promoted by co-feeding hydrocarbons generated from the Mo/HZSM-5 surface. The intentional separation of the catalyst and the gas-phase reaction at different temperatures (700 °C and 1020 °C) enables active and stable methane conversion via periodic reactions and regenerations. The linkage between MDA and MTOAH using 6Mo/HZSM-5 (30), which notably contributed to increasing the C2 production in MTOAH, was stabilized with 8.2% methane conversion during 49.5 h of the periodic CH₄ reaction-H₂ regeneration cycle. This study provides a new direction for achieving the efficient and carbon-neutral conversion of methane into useful chemicals.