Hierarchical Mo/HTNU-9 boosts methane aromatization with mitigated carbon deposition

Methane dehydroaromatization (MDA) offers a promising route for converting methane into aromatics, yet rapid catalyst deactivation via coking remains a critical barrier. This study addresses this challenge through TPAOH-assisted hierarchical pore engineering of HTNU-9 zeolite. Controlled desilication (0.25 mol/L TPAOH, 24 h) generates micro-mesoporous Mo/HTNU-9-24 while retaining microporous integrity, achieving a 22 % increase in methane conversion (14.7 % vs. 11.4 % for pristine Mo/HTNU-9) at 700 °C. The hierarchical architecture enhances mass transfer and Mo dispersion via synergistic effects. Silanol-rich mesopore surfaces and mild alkalinity stabilize Mo species, selective removal of strong acid sites coupled with spatial confinement of mesopores mitigate coke accumulation. The optimized catalyst exhibits prolonged stability due to restricted Mo agglomeration and efficient carbon precursor diffusion. These findings establish a dual strategy (pore topology control and acid site modulation) to synchronize active center dynamics and coke resistance, advancing the rational design of hierarchical zeolites for industrial MDA applications. Hierarchical Mo/HTNU-9-24, engineered via TPAOH-assisted desilication, integrates micro-mesoporous networks for optimized Mo dispersion and accelerated product diffusion. Mo/HTNU-9-24 achieves a 22 % boost in CH 4 conversion (14.7 %) and prolonged stability. • TPAOH-assisted hierarchical TNU-9 has been successfully prepared. • Methane conversion reached 14.7 % over Mo/HTNU-9-24. • Mo/HTNU-9-24 shows better catalytic stability than pristine Mo/TNU-9.