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研究了用甲烷和乙烷碳化预处理对Mo/HZSM-5催化甲烷转化成芳烃和乙烯的起始反应温度的影响。催化剂经甲烷在973 K或经乙烷在873 K碳化30min后,可使甲烷催化转化成苯和C_2烃的起始反应温度降低约100K。催化剂用烃类的碳化预处理过程不仅导致了钼物种的价态变化,而且可能导致了碳化钼的生成并引起催化剂化学本性的变化。通过催化剂在甲烷及氢气气氛下的差热分析及甲烷在催化剂上程序升温表面反应产物分析证实了钼物种的化学变化过程。
The effect of carbonation pretreatment with methane and ethane on the initial reaction temperature for the conversion of methane to aromatics and ethylene over Mo / HZSM-5 was studied. The initial reaction temperature for the catalytic conversion of methane to benzene and C 2 hydrocarbons by methane at 973 K or ethane at 873 K for 30 min is approximately 100 K lower. The carbonization pretreatment of hydrocarbons for catalysts not only leads to valence changes of the molybdenum species, but may also lead to the formation of molybdenum carbide and cause changes in the chemical nature of the catalyst. The chemical analysis of the molybdenum species was confirmed by differential thermal analysis of the catalyst in methane and hydrogen atmosphere and by the analysis of the reaction products of methane on the catalyst.