Here is an in-depth overview of recent advancements in ZSM-35 catalyst technology, presented in English:
China Catalyst Holdings Co., Ltd. has pioneered a novel preparation method for modified ZSM-35 molecular sieve catalysts. This innovative approach involves extrusion molding, drying, calcination, and treatment with acidic solutions, significantly improving the catalyst's thermal stability and selectivity. Experimental data demonstrate that the modified catalyst outperforms commercially available industrial ZSM-35 in terms of olefin conversion, selectivity, and yield during n-butene isomerization reactions. This breakthrough not only reduces production costs but also lays a solid foundation for large-scale applications.
The company has further advanced the field by patenting a binder-free ZSM-35 catalyst. By optimizing the mixing process of silica, alumina, alkali sources, pore-expanding agents, and water, this catalyst can be prepared without the need for molecular sieve crystal seeds as inducers. The binder-free design minimizes impurity introduction, enhancing the catalyst's purity and activity. It exhibits superior olefin conversion and selectivity compared to conventional ZSM-35 and is suitable for large-scale factory production, offering a new paradigm for high-performance catalyst preparation.
Continuous optimization of ZSM-35 catalyst preparation processes has enabled precise control over pore structure, acid distribution, and crystallinity by adjusting parameters such as the silica-to-alumina ratio, water-to-silica ratio, and crystallization temperature. A high silica-to-alumina ratio reduces the number of aluminum atoms in the framework, lowering acid center density and enhancing thermal stability and coke resistance. High specific surface areas (≥300 m²/g) and high crystallinity (≥95%) ensure the integrity and stability of the catalyst's framework structure, providing a robust foundation for efficient catalytic reactions.
The application scope of ZSM-35 catalysts has expanded beyond traditional petrochemical and fine chemical industries to encompass environmental protection, new energy, and pharmaceutical sectors:
