The need for on-purpose techniques for the conversion of cheaper and abundant light alkanes to petrochemical products has revitalized research interests on light alkanes aromatization. Here ethane/propane aromatization and ethylene oligomerization over the representative Zn-HZSM-5 and Pt/HZSM-5 catalysts have been studied by the step-perturbation transients to provide insight into the kinetics and mechanisms leading to higher olefins and aromatics formation from ethane aromatization. The time-dependent catalytic behavior during the build-up and back-transient between ethane and inert, ethane and propane, as well as ethylene and inert, has been extensively discussed. We suggested that the hydrocarbon-pool mechanism be involved once ethylene was produced from the dehydrogenation of ethane. The oligomerization/cracking, cyclization, and dehydrogenation/hydride transfer reactions involved with the hydrocarbon-pool species reach the thermodynamic equilibrium quickly. The initial ethane dehydrogenation and the final formation of aromatics from their corresponding intermediates are slow surface-reactions. The rate constants k for benzene, toluene, and xylene formation from the “lumped hydrocarbon-pool” have been evaluated based on the first-order kinetic model of the back-transient. The rate constants k for aromatics over the Pt⁰ clusters/particles in the Pt/HZSM-5 are ⁓ 20–30% higher than that over the Zn (II) cations in the Zn-HZSM-5 catalyst.

对于将廉价和丰富的轻质烷烃转化为石油化工产品的专用技术的需求，激发了对轻质烷烃芳构化的研究兴趣。在此，通过分步扰动瞬态研究了具有代表性的Zn-HZSM-5和Pt / HZSM-5催化剂上的乙烷/丙烷芳构化和乙烯低聚，以深入了解动力学和机理，从而从乙烷芳构化中生成更高的烯烃和芳烃。在乙烷和惰性气体，乙烷和丙烷以及乙烯和惰性气体之间的建立和反向过渡过程中，随时间变化的催化行为已得到广泛讨论。我们建议，一旦乙烷脱氢产生乙烯，就应参与碳氢化合物库机制。低聚/裂解，环化，与烃池物质有关的脱氢/氢化物转移反应很快达到热力学平衡。乙烷的初始脱氢和由其相应的中间体最终形成芳烃的反应很慢。速率常数根据反向瞬态的一级动力学模型，评估了“集总烃池”中苯，甲苯和二甲苯的形成k。在Pt / HZSM-5中，Pt ⁰团簇/颗粒上的芳香族化合物的速率常数k比Zn-HZSM-5催化剂中的Zn（II）阳离子的速率常数高20-30％。