Catalytic performance of Na-Mn2O3-based catalysts towards oxidative coupling of methane

Catalytic Routes for Direct Methane Conversion to Hydrocarbons and Hydrogen: Current State and Opportunities

“…Moreover, the C2 selectivity is enhanced by the addition of alkaline and alkaline earth metals Figure shows the performances of common MnNaW, La 2 O 3 , and Li-MgO catalysts in comparison to recently explored materials in the OCM process, and the main results are summarized in Table . − ,− …”

“…Important review papers reveal the particularities of the OCM reaction in detail. ,− Specific attention to the OCM process engineering and the reaction mechanism has been paid and will be discussed in this review. More specifically the nature of the catalysts and supports with a significant impact on the reaction will be considered. ,− In addition, the impact of several parameters such as temperature, space velocity, dilution, and others will be addressed, and preferable conditions favoring the OCM reaction will be revealed. Furthermore, the CH 4 /O 2 ratio appears as a highly important parameter directly affecting conversion, C2, and CO x selectivities.…”

Ce-Driven Ce-MnOx/Na2WO4/SiO2 Composite Catalysts for Low-Temperature Oxidative Coupling of Methane

“…18,19 Even though a deep study was made on the active sites of Mn/Na 2 WO 4 /SiO 2 , the contribution of active components to catalytic performance remains controversial. 10,11,20 In recent years, most researchers have confirmed that Mn 2 O 3 , Na 2 WO 4 , and α-cristobalite are interdependent, 21 and Na, W, and Mn need to exist at the same time and in close proximity to play a synergistic role and show better catalytic activity. 22,23 Therefore, the development of low-temperature and active-component-separated methane oxidative coupling catalysts is crucial for the clear study of catalyst components.…”

“…At the same time, catalysts containing MnO x have higher activity and are more conducive to the formation of C 2 species . However, Wachs et al believed that the catalytic active sites responsible for the activation of both CH 4 and O 2 for the formation of C 2 products are isolated, pseudotetrahedral, Na-coordinated WO 4 surface sites (Na-WO 4 ) on the SiO 2 support, and further confirmed that the surface Na-WO x site is responsible for selectively activating CH 4 to C 2 H x . , Even though a deep study was made on the active sites of Mn/Na 2 WO 4 /SiO 2 , the contribution of active components to catalytic performance remains controversial. ,, In recent years, most researchers have confirmed that Mn 2 O 3 , Na 2 WO 4 , and α-cristobalite are interdependent, and Na, W, and Mn need to exist at the same time and in close proximity to play a synergistic role and show better catalytic activity. , Therefore, the development of low-temperature and active-component-separated methane oxidative coupling catalysts is crucial for the clear study of catalyst components. Metal oxides can have enormous potential as supports or active components in high-performance catalysts, − among which MnO x is usually used as a catalyst for methane combustion.…”