Oxidative coupling of methane (OCM): An overview of the challenges and opportunities for developing new technologies

This review discusses the thermodynamic and kinetic limitations that currently make the oxidative coupling of methane (OCM) industrially inviable. We analyze some promising strategies to overcome such limitations. We present a brief screening of the OCM catalysts, focusing on crucial aspects to improve their catalytic performance: methane and oxygen activation, acid-base properties, tuning electronic properties by doping, mixed oxides, and nanostructured materials. We especially discuss the current understanding of the Mn–Na2WO4/SiO2 catalyst by contrasting the well-consolidated literature against recent fast-developing in situ/operando studies. Finally, we analyze membrane reactors and monolith-supported catalysts as engineering approaches to manage thermal and kinetic OCM issues.