Facile and template-free synthesis of robust, highly active and easily recyclable submicrometer-sized hierarchical TS-1 aggregates composed of ultra-small nanocrystallites (<50 nm)

Abstract

Based on additional freeze-drying of gel precursors and routine steam assisted crystallization (SAC) treatment, submicrometer-sized hierarchical TS-1 aggregates named as aggTS-1 were facilely synthesized for the first time. The resultant materials were composed of ultra-small TS-1 nanocrystallites (<50 nm), which were robust and showed high crystallinity, abundant stacked mesopores and preferential surface distribution of active titanium sites. Consequently, they showed the advantages of easy isolation, high activity and recyclability in subsequent model reactions of catalytic oxidative desulfurization of fuel oils. Additionally, the critical effect of water concentration on the particle morphology and formation process of nanozeolite aggregates was confirmed.