【摘要】 在总压1.03atm.下研究了钼酸铋催化剂上的丙烯氧化动力学。在315—440℃的温度范围内,生成丙烯醛反应的表观活化能为26—27Kcal/mole。当丙烯分压低于0.3atm时,丙烯醛的生成速度和丙烯的消耗速度对丙烯分别为0.87级和0.86级;当氧分压低于0.3atm.时,丙烯醛的生成速度和丙烯的消耗速度对氧分别为0.4和0.5级。当丙烯和氧的分压较高时,(P_O2>0.3atm,P_C3H6>0.3atm)上述反应速度无论对丙烯还是对氧均不表现为简单的反应级数关系。反应速度存在着极大值。依据本文实验结果,建议了双位表面反应为速度控制步骤的Redox机理。在此基础上导出了丙烯醛生成速度的方程。较好地解释了实验结果。更多还原

【Abstract】 Under pressure of 1.03 atm. the kinetics of propylene Oxidation over a Bismuth Molybdate Catalyst has been investigated. In the temperature range 315℃-440℃,the apparent activition energy of acrolein formation was 26-27 kcal/mole. When the partial pressure of propylene was, lower than 0.3 atm. the apparent reaction order of acrolein formation was 0.87 for propylene and that of propylene consumption was 0.86 for propylene. When the partial pressure of oxygen was less than 0.3 atm the reaction orders of acrolein formation and of propylene consumption were 0.4 and 0.5 for oxygen respectively. But when the partial pressures of both propylene and oxygen were all higher than 0.3 atm., no simple order was observed in the reactions. The rate of the reaction exhibits a maximum.It has been suggested that the reaction proceeds via a Redox mechanizm, in which the rate-limiting step is the interaction between two surface species. On this basis the rate equation of acrolein formation was developed, with which the experimental results got a better explanation.更多还原