Enhancing C–H Bond Activation of Methane via Temperature-Controlled, Catalyst–Plasma Interactions

Recent shale gas discoveries and advances in plasma chemistry provide the basis to exploit metal surface–plasma interactions to precisely control C–H bond activation on catalytic surfaces, leading to improved reaction efficiencies. Although the exact determination of plasma–catalyst interactions remains a topic of continuing research, this Letter provides evidence that plasma–catalyst interactions exist and can be used to significantly enhance the activation of C–H bonds at temperatures >630 K, probed by the catalytic dry reforming of methane with carbon dioxide using Ni/Al2O3. We systematically varied bulk temperature and plasma power to determine Ni–plasma interactions. In contrast to reactions at low temperatures (<630 K), CH4 conversion, H2 yield (selectivity), and forward CH4 consumption rate were significantly enhanced at higher temperatures with plasma (>8 fold increase). Other competing contributors, such as gas-phase plasma reactions, charge confinement, and plasma-driven enhanced bulk gas temperatures, played minor roles when operating at temperatures >630 K.