A 4-step kinetic model of CO₂-assisted oxidative dehydrogenation (ODH) of propane to C₂/C₃ olefins over a novel MoO_x/La₂O₃–γAl₂O₃ catalyst was developed. Kinetic experiments were conducted in a CREC Riser Simulator at various reaction temperatures (525–600 °C) and times (15–30 s). The catalyst was highly selective towards propylene at all combinations of the reaction conditions. Langmuir-Hinshelwood type kinetics were formulated considering propane ODH, uni- and bimolecular cracking of propane to produce a C₁-C₂ species. It was found that the one site type model adequately fitted the experimental data. The activation energy for the formation of propylene (67.8 kJ/mol) is much lower than that of bimolecular conversion of propane to ethane and ethylene (303 kJ/mol) as well as the direct cracking of propane to methane and ethylene (106.7 kJ/mol). The kinetic modeling revealed the positive effects of CO₂ towards enhancing the propylene selectivity over the catalyst.

中文翻译：

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流化床中 MoOx/La2O3–Al2O3 上丙烷与 CO2 氧化脱氢的动力学模型

开发了新型 MoO _x /La ₂ O ₃ –γAl ₂ O _{3催化剂上 CO 2}辅助丙烷氧化脱氢 (ODH) 生成 C ₂ /C ₃烯烃的 4 步动力学模型。动力学实验在 CREC 立管模拟器中在不同的反应温度 (525–600 °C) 和时间 (15–30 s) 下进行。该催化剂在反应条件的所有组合下对丙烯具有高选择性。Langmuir-Hinshelwood 型动力学是考虑到丙烷 ODH、丙烷的单分子和双分子裂解以产生 C ₁ -C ₂物种。结果发现，单点类型模型充分拟合了实验数据。生成丙烯的活化能（67.8 kJ/mol）远低于丙烷双分子转化为乙烷和乙烯的活化能（303 kJ/mol）以及丙烷直接裂解为甲烷和乙烯的活化能（106.7 kJ/摩尔）。动力学模型揭示了 CO ₂对提高丙烯相对于催化剂的选择性的积极作用。