Methane pyrolysis on deposited resistive MeOx/carborundum catalysts, where MeOx is MgO, CaO, MgO/Al2O3, MgO/ZrO2, CaO/Al2O3, and CaO/ZrO2

Resumo

Thermostable oxide catalysts (Al₂O₃, ZrO₂, MgO, and CaO) deposited onto a resistive support (carborundum) are investigated for oxygen-free methane pyrolysis. Adding MgO, ZrO₂, and Al₂O₃ to pure carborundum considerably improves methane conversion and selectivity toward acetylene. In contrast, the deposition of СаO reduces the total activity of deposited catalysts. The maximum selectivity toward acetylene (23.6%) is achieved on MgO/SiC catalyst with methane conversion of 68% at T = 1290°C. Examination of the MgO/SiC sample shows that the catalyst retains its catalytic characteristics without decomposition (methane conversion, ≈69%; selectivity toward acetylene, ≈22%) for more than 4 h of operating in methane pyrolysis (15% СН₄ in nitrogen) at a temperature of 1300°С as a result of there being no carbon corrosion of the carborundum resistive support, in comparison to the metal catalysts.