Solvent-derived defects suppress adsorption in MOF-74.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 37185270.
- Also identified by DOI 10.1038/s41467-023-38155-8 and PMC identifier 10130178.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Defects in metal-organic frameworks (MOFs) have great impact on their nano-scale structure and physiochemical properties. However, isolated defects are easily concealed when the frameworks are interrogated by typical characterization methods. In this work, we unveil the presence of solvent-derived formate defects in MOF-74, an important class of MOFs with open metal sites. With multi-dimensional solid-state nuclear magnetic resonance (NMR) investigations, we uncover the ligand substitution role of formate and its chemical origin from decomposed N,N-dimethylformamide (DMF) solvent. The placement and coordination structure of formate defects are determined by <sup>13</sup>C NMR and density functional theory (DFT) calculations. The extra metal-oxygen bonds with formates partially eliminate open metal sites and lead to a quantitative decrease of N<sub>2</sub> and CO<sub>2</sub> adsorption with respect to the defect concentration. In-situ NMR analysis and molecular simulations of CO<sub>2</sub> dynamics elaborate the adsorption mechanisms in defective MOF-74. Our study establishes comprehensive strategies to search, elucidate and manipulate defects in MOFs.