Breaking the conversion-selectivity trade-off through a plasma reaction-separation coupling process

Using CH₄ under ambient conditions remains a major challenge. Although energetic electrons in non-thermal plasma can activate their C–H chemical bonds at ambient temperature and pressure, the target oxygenates are more reactive than the reactants, inevitably leading to excessive oxidation in the plasma. The limited yield restricts their industrial application. Herein, we have designed a plasma reaction mode to realize a plasma reaction-separation coupling technology capable of protecting intermediate products through facile separation to break the conversion-selectivity trade-off. Coupling the high-space-velocity cyclic process with plasma technology can further increase the yield of liquid fuel and reduce the formation of the overoxidation product CO₂. This advancement strengthens the viability of plasma for the selective oxidation of methane for industrial applications.