Shaped catalysts are crucial in fixed-bed olefin epoxidation processes, yet conventional shaping methods using inert binders often dilute active sites and block the micropores of zeolites. Herein, we report a facile alternating vapor–liquid recrystallization (AVLR) strategy for fabricating a binder-free, fully crystalline, and spherical-shaped catalyst (TS-1-B-VL) with abundant hollow cavities. Starting from conventional binder-containing TS-1 spheres (TS-1-B), the AVLR process effectively converts the amorphous silica binder into zeolite and induces the recrystallization of the TS-1 zeolite. This process significantly enhances the relative crystallinity, creates intracrystalline mesopores, and substantially improves the crush strength. The resulting TS-1-B-VL catalyst exhibits exceptional activity and stability in the epoxidation of 1-hexene using H2O2 as the oxidant. This study demonstrates that the AVLR is a versatile and efficient route for producing high-performance zeolite catalysts with great industrial potential.
Yang et al. (Tue,) studied this question.