In this work, the catalytic mechanisms of methylcyclohexane (MCH) cracking and light olefins production were systematically investigated over three zeolites catalysts of Si-ZSM-5, hydrated ZSM-5 and HZSM-5. HZSM-5 exhibited the highest activity in terms of MCH conversion and selectivity towards light olefins. The mechanisms of MCH activation over HZSM-5 show that protolytic ring-opening is more energetically favorable when compared to protolytic dehydrogenation and thermal cracking. Four distinct pathways can result in the production of light olefins. But the pathway for the productions of propylene and butane is energetically favorable. Both protolytic C–C bond cleavage and the regeneration of the Brønsted acid site significantly influence production of light olefins. The rate-limiting steps for protolytic ring-opening and the production of light olefins are the initial protonation of C–C bonds. We hope this work can provide potential significance in understanding the hydrocarbon fuels cracking and aiding in identifying target products.

中文翻译：

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沸石甲基环己烷裂解制轻质烯烃的催化机理

本工作系统研究了Si-ZSM-5、水合ZSM-5和HZSM-5三种沸石催化剂的甲基环己烷（MCH）裂解和轻质烯烃生产的催化机理。 HZSM-5 在 MCH 转化率和轻质烯烃选择性方面表现出最高的活性。 HZSM-5 上的 MCH 活化机制表明，与质子脱氢和热裂解相比，质子分解开环在能量上更加有利。四种不同的途径可以产生轻质烯烃。但丙烯和丁烷的生产途径在积极方面是有利的。质子化 C-C 键断裂和布朗斯台德酸位点的再生都显着影响轻质烯烃的生产。质子开环和轻质烯烃生产的限速步骤是 C-C 键的初始质子化。我们希望这项工作能够为了解碳氢化合物燃料裂解和帮助识别目标产品提供潜在意义。