Synthesis and Catalytic Performance of Short b-Axis ZSM-5 Zeolite Regulated by Seed and Fluoride Ion

Evaluation of the bifunctional catalyst constructed by compounding SS-3 with Fe-Mn oxide (FM) for CO₂ hydrogenation to aromatics showed that the proportion of aromatics in the C5+ products of the FM/SS-3 catalyst system reached 83.5%, and the aromatics selectivity (53.5%) was more than twice that of the commercial micrometer-sized zeolite system. During a 100 h continuous operation, the FM/SS-3 catalyst exhibited excellent stability, with a coke weight loss of only 8.7% for the spent zeolite (compared to 12.2% for the commercial sample).

This is mainly attributed the combined advantages of the short b-axis morphology, increased external specific surface area, and the resulting improved accessibility of active sites, which promotes the rapid desorption and escape of aromatic molecules generated by olefin aromatization, and inhibits secondary deep condensation and carbon deposition deactivation caused by diffusion limitations. This work provides fundamental experimental data for the controllable synthesis of short b-axis ZSM-5 zeolites and their application in CO2 hydrogenation to aromatics.