Spatio‐Chemical Heterogeneity of Defect‐Engineered Metal–Organic Framework Crystals Revealed by Full‐Field Tomographic X‐ray Absorption Spectroscopy

Abstract

The introduction of structural defects in metalorganic frameworks (MOFs), often achieved through the fractional use of defective linkers,i se merging as am eans to refine the properties of existing MOFs.T hese linkers,m issing coordination fragments,c reate unsaturated framework nodes that may alter the properties of the MOF.Aproperty-targeted utilization of this approach demands an understanding of the structure of the defect-engineered MOF.W ed emonstrate that full-field X-raya bsorption near-edge structure computed tomography can help to improve our understanding.T his was demonstrated by visualizing the chemical heterogeneity found in defect-engineered HKUST-1 MOF crystals.Anonuniform incorporation and zonation of the defective linker was discovered, leading to the presence of clusters of as econd coordination polymer within HKUST-1. The former is suggested to be responsible,i np art, for altered MOF properties; thereby, advocating for aspatio-chemically resolved characterization of MOFs.