Effect of the particle blending-shaping method and silicon carbide crystal phase for Mn-Na-W/SiO2-SiC catalyst in oxidative coupling of methane

Supported Mn-Na-W on silica is a benchmark catalyst for oxidative coupling of methane due to its appropriate ethylene yields. Here we compare eight catalysts with the same active phase (Mn-Na-W) and variable support composition or particle blending-shaping method to evaluate the effect of the support. First, we explore the different preparation methods (impregnation, ball milling, and spray-drying), concluding that spray-drying leads to a promising selective catalyst. Then, we compare different SiC crystal phases (alpha+beta and beta), keeping the same composition and shaping method (spray-drying). The catalyst with alpha+beta SiC crystal phase has significantly more activity than the beta one in 30 h reaction runs. Finally, we assess the effect of process conditions to improve the yields (15 % at 800?C) of the most promising catalyst: spray-dried and with alpha+beta SiC. The roles of the blending shaping method and SiC crystal phase are explained by the induced differences in oxidation behavior and active phase distributions.

Automated summary

This article investigates the effect of the support on the catalyst for the oxidative coupling of methane. The study shows that catalysts prepared using the spray-drying method exhibit promising selective catalytic performance. Additionally, the catalyst with the α+β SiC crystal phase demonstrates significantly higher activity compared to the β phase. The most promising catalyst is prepared using the spray-drying method and contains the α+β SiC crystal phase.