Rapid Generation of Metal–Organic Framework Phase Diagrams by High-Throughput Transmission Electron Microscopy

Abstract

Metal−organic frameworks (MOFs) constructed from Zr 6 nodes and tetratopic carboxylate linkers display high structural diversity and complexity in which various crystal topologies can result from identical building units. To determine correlations between MOF topologies and experimental parameters, such as solvent choice or modulator identity and concentration, we demonstrate the rapid generation of phase diagrams for Zr 6 -MOFs with 1,4-dibromo-2,3,5,6-tetrakis(4-carboxyphenyl)benzene linkers under a variety of conditions. We have developed a full set of methods for high-throughput transmission electron microscopy (TEM), including automated sample preparation and data acquisition, to accelerate MOF characterization. The use of acetic acid as a modulator yields amorphous, NU-906, NU-600, and mixed-phase structures depending on the ratio of N,N-dimethylformamide to N,N-diethylformamide solvent and the quantity of the modulator. Notably, the use of formic acid as a modulator enables direct control of crystal growth along the c direction through variation of the modulator quantity, thus realizing aspect ratio control of NU-1008 crystals with different catalytic hydrolysis performance toward a nerve agent simulant.

Understanding and controlling the nucleation and growth of metal–organic frameworks

“…Such studies would provide essential, transferable studies to industry which often use high pressure and temperature processing conditions. As we continue to develop high-throughput characterization methods, such as with the recent development of high-throughput TEM, 186 the size in which data sets can be generated will advance, allowing translatable findings to a greater range of systems.…”

Amorphous MOFs for next generation supercapacitors and batteries

“…Solvent, reaction time, pH, type of metal salt precursors, metal to ligand ratios and concentration can all impact the crystallinity of MOFs. 52…”

“…Solvent, reaction time, pH, type of metal salt precursors, metal to ligand ratios and concentration can all impact the crystallinity of MOFs. 52 A synthesis route that is only applicable to a subgroup of amorphous MOFs is melt-quenching. This process requires the MOFs to have an accessible melting temperature that is below its decomposition temperature.…”

Understanding ZIF particle chemical etching dynamics and morphology manipulation: in situ liquid phase electron microscopy and 3D electron tomography application

“…These factors include the influence of the solvent, reaction conditions, and the incorporation of additives. 4,6,7 By gaining insights into the MOF growth mechanism, researchers can develop strategies to control the MOF particle morphology and tailor the properties of the resulting materials for specific applications. 8 For morphology control, traditionally, ZIF-8 is synthesized through [9][10][11] 7 different methods.…”