engleski

Mechanochemical synthesis of a microporous MOF-74 metal-organic framework studied by in situ synchrotron X-ray diffraction

Here we report the mechanistic study of mechanochemical synthesis of microporous MOF-74 from ZnO. The MOF-74 frameworks (also known as a CPO-27) are a particularly important family of MOFs made from bivalent metal nodes and 2, 5- dihydroxyterephthalic acid anions. Structures of these MOFs are characterized by honeycomb architecture and free metal sites, with reports showing high catalytic acitivty and potential for gas separation. In situ XRPD studies, performed at the European Synchrotron Radiation Facility (ESRF) and Deutsches Elektronen Synchrotron (DESY) revealed that the mechanosynthesis of Zn- MOF-74 proceeds over two steps, initially yielding a non-porous coordination polymer which reacts with remaining ZnO to yield Zn-MOF-74 whose porosity exceeds previously reported materials. Such unprecedented close-packed open reaction pathway can be ascribed to difference in acidity of hydroxyl and carboxylate functionalities on the ligand, and we believe can lead to completely new MOF materials with unprecedented properties.

mechanochemical synthesis; microporous metal-organic materials; MOF-74; in situ methods

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