Modeling the influence of hierarchical ZSM-5 pore architecture on global reaction: Predictive simulation of n-pentane catalytic cracking for light olefin production

This study establishes ZSM-5 zeolite as a pivotal catalyst for naphtha catalytic cracking, where pore structure modulation critically governs high-selectivity olefin generation. Employing hierarchical ZSM-5 catalysts with adjustable micro/mesopore ratios synthesized via a dual-template approach, we developed a global reaction model incorporating catalyst pore property parameters to predict ethylene (C₂H₄) and propylene (C₃H₆) yields from cracking of n-pentane. First, the mathematical formalism of the global reaction model was derived from product distributions, explicitly correlating zeolite pore characteristics with reaction kinetics. Subsequently, six pore descriptors were evaluated across 28 combinatorial scenarios. The model identified the optimal parameter ensemble mesoporous surface area (S_meso), total surface area (S_BET), pore volume ratio (V_meso/V_total) governing light olefin yields with < 3.51 % deviation from experimental data. Model predictions further revealed that high V_meso/V_total ratios were essential for maximizing n-pentane conversion to light olefins, with C₂H₄ yield exhibiting differential sensitivity to S_meso and C₃H₆ yield to S_BET. This pore-integrated global model provides a foundational framework for the rational design of hierarchical ZSM-5 catalysts targeting high-efficiency naphtha cracking.