Low-Temperature Light-off MnO_x−Na₂WO₄-Based Catalysts: A Step Forward to OCM Process Industrialization**

Oxidative coupling of methane (OCM) catalyzed by MnO_x−Na₂WO₄-based catalysts has great industrial potential to convert CH₄ directly to C_2–3 products, but the high light-off temperature is a big challenge to OCM commercialization. The reaction mechanism studies disclosed that O₂/CH₄-activation relevant “Mn²⁺↔Mn³⁺” redox cycle is tightly linked with the catalyst light-off. One concept is thus put forward that the OCM light-off temperature could be lowered once a “Mn²⁺↔Mn³⁺” redox cycle was established to be triggered at low temperature over MnO_x−Na₂WO₄-based catalysts. The relevant studies in recent years are reviewed, showing that the establishment of low-temperature light-off “Mn²⁺↔Mn³⁺” redox cycle over the MnO_x−Na₂WO₄-based catalysts indeed works effectively toward a low-temperature light-off OCM process. Moreover, three perspectives for the OCM industrialization are discussed based on this concept, including monolithic catalyst, fluidized-bed method and chemical-looping process.