Research progress in Mn-Na2WO4/SiO2 catalysts for oxidative coupling of methane to ethylene
Ethylene production is an important indicator to measure the level of a country's petrochemical industry.The oxidative coupling of methane(OCM)process which converts methane to ethylene efficiently has become a research hotspot in the catalytic industry and energy field.However,the OCM reaction is a complex reaction network,which combines two steps of multi-phase reaction and homogeneous reaction,resulting in key challenges in the development of efficient catalysts for OCM reactions.The Na-W-Mn/SiO2 catalysts show high comprehensive performance.However,the components of Na-W-Mn/SiO2 are complex,which results in a controversy of the real active center during high reaction temperature.In this paper,we primary discuss the OCM mechanism reaction over Na-W-Mn/SiO2 catalysts,as well as the effects of oxygen species and acid-base properties on methane activation.The role of the active components over Mn-Na2WO4/SiO2 catalyst system is introduced in detail.And the application of various in-situ characterization methods in the study of OCM mechanism is also summaried.Finally,the future development trend of OCM reaction were summarized in the high-temperature in-situ characterization,low-temperature controllability and chemical chain cycling of OCM reaction.
methanecatalystOCMreaction mechanismactive site of Mn-Na2WO4/SiO2