Plasma-catalysis-enhanced dry reforming of methane facilitated by electrically conductive carbide catalysts.

Abstract

DRM process, despite its potential for sustainable H2 production, faces significant challenges due to high energy requirements and catalyst instability at temperatures exceeding 7000C. To address these issues, NTP (DBD-plasma) was used to process DRM reaction, and TMCs (specifically Mo2C and WC) were investigated as innovative catalysts for the reaction. Mo2C and WC catalysts were synthesized by mechanical activation process followed by molten-salt synthesis method, using different sizes of Mo or W powders (nano-powder vs. micro-powder), carbon sources (superactivated carbon vs. carbon black), and metal/carbon ratios. The results showed that Mo2C catalysts synthesized with micro-powder Mo and carbon black at a 1:1 metal/carbon ratio demonstrated exceptional catalytic activity, increasing H2 yield by 170% and CO₂ conversion by 277% compared to un-catalyzed reaction. Similarly, WC catalysts synthesized with nano-powder W and carbon black at a 1:1 ratio boosted H₂ yield by 40% and CO₂ conversion by 31%. The high electrical conductivity of TMCs, particularly Mo2C, facilitated high energy plasma discharge species’ transfer to the DRM reactants, thereby improved the interaction between plasma-generated reactive species and DRM reactants, and increased the overall feed-conversion and reaction-yield. Temperature in the discharge region also remained significantly low for the whole time-on-stream. This study effectively addressed the limitations of conventional thermal catalysis, promoting energy efficiency, enhancing catalytic performance, and improving operational stability, thus offering a promising pathway towards more sustainable and efficient methane reforming processes.