Chemical Looping Steam Reforming of Methane under Mild Conditions via Non-Thermal Plasma

The chemical looping steam reforming of methane (CL-SRM) holds immense potential for energy-efficient conversion of CH 4 into syngas and high-purity hydrogen. However, its large-scale implementation remains limited by high operating temperatures and substantial energy requirements. This paper describes a non-thermal plasma-mediated CL-SRM process based on CH 4 /H 2 O redox cycles over lanthanum-based perovskites under mild conditions. The developed process achieves efficient CH 4 activation at 600 °C, attaining 53.5% CH 4 conversion and 0.57 mmol∙g −1 H 2 with 92% purity over La 0.5 Ce 0.5 FeO 3 , while negligible conversion is observed under plasma-free conditions at the same furnace temperature. These performances surpass those observed under purely thermal conditions at 800 °C. Mechanistic insights reveal that plasma plays a crucial role in generating vibrationally excited CH 4 v species, thereby markedly lowering the reaction barrier for CH 4 activation. The plasma-mediated CL-SRM process delivers energy through voltage-induced electron transfer, offering the potential for adiabatic reactor designs that minimize energy consumption compared with conventional combustion-based systems suffering from heat transfer limitations.