Na2WO4/Mn/SiC Catalyst for Oxidative Coupling of Methane

Since the oxidative coupling of methane (OCM) is a high-temperature and highly exothermic reaction, the hot spot on the catalyst surface is easily formed during the reaction. The control of heat formed during the reaction is an important technique because the hot spot on the catalyst surface can degrade catalytic activity. Herein, Mn₂O₃-Na₂WO₄/SiC was prepared by using SiC with high thermal conductivity and good stability at high temperatures, and the catalyst was applied as a catalyst for OCM reaction. Two different Mn₂O₃-Na₂WO₄/SiC catalysts were prepared by the wet impregnation method using SiC supports with different particle sizes. For comparison, Mn₂O₃-Na₂WO₄/SiO₂ was also prepared by the same method. The catalysts were analyzed by nitrogen adsorption-desorption, XRD, FE-SEM, and HR-TEM. The properties of catalysts were evaluated by OCM reaction. The OCM reaction was carried out at a space velocity of 10,000 h^-1 in a fixed-bed reactor (CH₄/O₂/N₂ = 3/1/1, v/v/v). As a result, Mn₂O₃-Na₂WO₄/SiC catalyst showed 2 % increase in methane conversion and 2.3 % increase in C₂ yield than Mn₂O₃-Na₂WO₄/SiO₂ at 800 ℃.