VMgO催化剂上丙烷和异丁烷临氧催化转化机理

Mechanism of Propane and iso butane Oxidehydrogenation on VMgO Catalyst

用程序升温反应 -红外光谱技术研究 2 0VMgO和 6 0VMgO催化剂上丙烷和异丁烷临氧催化转化的机理 .结果表明 ,临氧条件下的反应性是异丁烷 >丙烷 ,与其分子中最弱C -H键键能从弱到强顺序相同 ,这意味着临氧活化的第一步可能是断裂分子中强度最弱的C -H键、且为速率控制步骤 ;丙烷临氧反应的深度氧化产物COx 与氧化脱氢产物丙烯的生成是平行和 (或 )连续反应关系 ,而裂解产物乙烯和甲烷的生成则是平行反应 ;异丁烷氧化脱氢反应中C -C键的断裂比丙烷的容易 .

The reactivation and transformation of propane and iso butane in the presence of oxygen on VMgO catalyst have been studied by temperature programmed reaction FTIR.The results showed that breaking of the second C-H bond of C 3H 8 and the tertiary C-H bond of i C 4H 10 may have been involved in the activation step,i.e.rate limited step for propane and iso butane oxidative dehydrogenation.In propane oxidehydrogenation CO x may either directly come from deep oxidation of propane,or come from consecutive oxidation of propene.While most of the cracking products ethene and methane are directly come from propane.The breaking of C-C bond in i C 4H 10 is easier than that in C 3H 8.