Hollow Zeolites-Confined Isolated (ZnOH)⁺ Enable High Selectivity and Stability for Methanol to Aromatics

The methanol-to-aromatics process has great potential to meet the growing global consumption for aromatics, but the widely used metal modified strong acid zeolites, such as Zn/ZSM-5, usually suffer from unsatisfactory aromatic selectivity and short time-on-stream stability. A new Zn/ZSM-5 based catalyst with only isolated (ZnOH)⁺ species and a cavity core was synthesized by using a new inorganic-organic hybrid aluminosilicates sphere, which was fabricated with the assistance of electrostatic assembly. Isolated (ZnOH)⁺ species can improve the selectivity to aromatics and minimize the negative influence of diffusion simultaneously. Meanwhile, the core cavity can provide more space to deposit coke. Thus, the prepared HL−Zn(DS)/HZSM-5 zeolite exhibited the superior aromatics selectivity of 50.63 % with a WHSV of 3.18 h⁻¹ at 390 °C and 0.5 MPa. Moreover, the catalyst can afford an extremely low deactivation constant of 0.0097 mg/h with an enhanced lifetime up to 131 h and strong regeneration ability.