(220e) Methane Dehydroaromatization over Mo/H-ZSM-5 Under Non-Thermal Plasma Stimulation

Non-thermal plasmas are promising alternatives to thermal processes that can activate stable gas molecules close to ambient temperatures by electron impact reactions. When a non-thermal plasma is coupled with a catalyst, reaction rates and selectivity towards desired products are further improved. Plasma activation approaches have been applied to the direct conversion of methane to value-added products since this stable molecule requires high energy input and elevated temperatures for activation. Methane dehydroaromatization (MDA) is a non-oxidative approach to directly convert methane into aromatics over a Mo/H-ZSM-5 catalyst, and an equilibrium conversion of 14% can be obtained at 973 K. However, high temperatures, coke deactivation and low-single pass methane conversions are major drawbacks associated with this process.

Here, a non-thermal plasma-catalytic methane dehydroaromatization process is presented, where we show that this chemistry can be performed at lower bulk gas temperatures, compared to the high temperatures required for methane conversion under thermal catalytic conditions. We observed that the bulk gas temperature directly influences the behavior of the plasma discharge, and led to lower methane conversions when catalysts were absent. However, incorporation of Mo/H-ZSM-5 in the plasma discharge significantly enhances methane conversion under these conditions, while shifting the product distribution toward the formation of aromatics. This presentation will highlight our current understanding of this plasma-catalytic methane dehydroaromatization mechanism and how plasma stimulation can facilitate methane dehydroaromatization pathways at lower reaction temperatures over a Mo/H-ZSM-5 catalyst.