Study on the coke deposition characteristics of hierarchical ZSM-5 zeolites with synergistic regulation of pore structure and temperature in benzene catalysis

• • TEAOH treatment at 0.4 mol/L (ZSM-5-C) increased total pore volume from 0.24 to 0.43 cm3/g and Brønsted acid sites from 0.28 to 0.67 mmol/g, enhancing acid site accessibility; this directly improves catalytic activity and coke resistance in industrial benzene conversion. • • ZSM-5-C exhibited a coke amount of 4.0%, versus 11.9% for parent microporous NL-ZSM-5, a threefold reduction; this translates to extended catalyst lifetime and reduced regeneration frequency in fixed-bed reactors. • • Molecular dynamics simulations showed benzene diffusion coefficient in 3.0 nm mesopores is an order of magnitude higher than in 2.0 nm mesopores, while adsorption capacity decreases with larger mesopores; this shortens molecular residence time, mitigating deep condensation reactions that lead to coke. • • Increasing reaction temperature exponentially intensifies surface condensation reactions (Arrhenius effect), which dominates coke formation; however, hierarchical pore structure effectively mitigates this negative effect, enabling operation at higher temperatures without proportional coke penalty.