Continuous synthesis of ZIF-67 by a microchannel mixer: A recyclable approach

Microfluidic synthesis of a Zeolitic-Imidazole Framework ZIF-67 at ambient temperature and pressure is reported. With a metal/ligand/triethylamine (TEA) ratio of 1/4/4, ZIF-67 can be produced with a high space-time yield (STY) of 57000 kg m(-3) d(-1) and a production rate of 285 g h(-1) in ethanol. It can be produced with a similar STY in water solution as well. Given the importance of sustainable synthesis, the recycling process of the mother liquor was investigated. The mother liquor can be recycled 5 times with high yield and crystallinity in ethanol, but not applicable in water solution. The morphology and particle sizes of ZIF-67 can be regulated in a controlling manner in a water-ethanol mixed solvent. Moreover, the influence of TEA on the characteristic of the ZIF-67 structure was investigated in detail.

Automated summary

The microfluidic synthesis of a Zeolitic-Imidazole Framework ZIF-67 at ambient temperature and pressure with a high throughput and recycling ability has been reported. The mother liquor can be recycled multiple times in ethanol, but not in water solution. Control over the morphology and particle sizes of ZIF-67 can be achieved in a water-ethanol mixed solvent. Additionally, the influence of TEA on the ZIF-67 structure was investigated in detail.