Fast Syntheses of MOFs Using Nanosized Zeolite Crystal Seeds In Situ Generated from Microsized Zeolites

Abstract

Herein, we report a seeded growth methodology using zeolite crystal seeds for the rapid hydrothermal syntheses of MOFs. Common microsized zeolite crystals without surface modification are added to the hydrothermal synthesis systems of MOFs and break into nanosized zeolite crystal seeds under the MOF hydrothermal synthesis conditions. Nanosized zeolite seeds can offer enormous surface areas to nucleate MOFs and the in situ generation way can avoid aggregation and separation troubles relevant to nanosized zeolite production. Fast syntheses of MIL-101(Cr), MIL-100(Cr), MIL-104(Co), and MIL-53(Fe) were carried out by employing zeolite MOR, Y, or ZSM-5 crystal seeds. Typically, only about 1.3 wt % microsized zeolite MOR crystals relative to the metal and ligand precursors for MIL-101 formation can shorten the crystallization complete time by 75% compared to the conventional MIL-101 crystallization without adding zeolites. This nanosized zeolite seed-assisted growth methodology is an important step toward the industrial scale-up of MOF synthesis. Simultaneously, it builds a bridge between MOFs and zeolites, which may shed light on the preparation of composite materials composed of MOFs and zeolites.