Insights into the Reaction of 1‑Butene Catalytic Cracking in HZSM‑5 from First-Principles: Reaction Mechanism and Microkinetics Research

In this study, the mechanism and microkinetics of 1-butene catalytic cracking were investigated. Based on the calculation results of the full reaction, the optimal paths for 1-butene isomerization and dimerization-cracking were clarified, and a new aromatization mechanism is proposed. In addition, the effect of reaction temperature variation on the product distribution was clarified. Limited by the amount of 1-butene adsorbed, increasing the temperature will gradually change the rate-determining step of the system and have negative effects on the reaction rate. In the temperature range suitable for the production of ethylene and propylene, this effect becomes very significant. Therefore, appropriately increasing the number of Brønsted acid sites in the catalyst to ensure high adsorption amount of 1-butene at high temperatures is an effective way to improve the production of ethylene and propylene in catalytic cracking of butene.