Defect-Engineered Paddle-Wheel based Metal-Organic Frameworks (DE-MOFs)
Physical Chemistry of Solids and Surfaces, Material Characterisation
Theoretical Chemistry: Molecules, Materials, Surfaces
Final Report Abstract
The collaborative project aimed at the rational generation and detailed characterization of modified coordinatively unsaturated metal sites, i.e. Mn+ framework (node) sites, in the volume of paddle wheel based (as secondary building units) Metal-Organic Framework materials (MOFs). A major objective was the development of a multiscale simulation methodology for the understanding of the formation of different kinds of defects (missing linkers and nodes, defective nodes, hierarchical porosity) including disorder and structural heterogeneity and defect correlation as function of the defect generating components (linkers) used in the synthesis of the MOF materials. Another major goal was to experimentally identify unique properties of the so-called DE-MOFs as a consequence of the defect structure being absent in the parent MOF. The perspective was to derive an overarching atomistic understanding of defect engineering for the chosen case studies and transfer to other MOFs. From the obtained experimental and theoretical results within this project one can conclude that MOFs are intrinsically very tolerant to both missing node defects (large pores) or the introduction of defect linkers, and such non-ideal structures are likely to form. The theoretical results confirm the experimental observation of a formation of framework structures resembling the non-defective parent compounds up to a large degree of implementation of defect generating linkers and influencing the adsorption and catalytic properties. In particular, the expected effects of implementing defect generating linkers to Paddle-Wheel based MOFs (derivatives and congeners of the HKUST-1 structure type) was substantiated. Concept transfer from the Cubased HKUST-1 model system to precious group metal derivatives (PGM = Ru, Rh) and the Cu-based, NOT-100 system of different topology was established. However, it turned out that the truncated linker concept for defect implementation generates a huge demand in linker synthesis and in detailed compositional and microstructural characterization of the DE-MOF samples. The scalability of this approach for a wider defect engineering of MOFs in general appears to be limited. In particular, thermal defect engineering of PGM-MOFs of the HKUST-1 structure type proved a very powerful strategy of implementing missing linker and modified node defects. This strategy is likely to offer more flexibility and scalability unless it lacks the molecular precision of the truncated linker (defect generating) approach. In summary, the major outcome of our project points to the still huge demand for a deeper conceptional understanding of MOF defect engineering, as we also pointed out in our review articles on the topic. Many questions about the thermodynamics of compositional complex and defect rich coordination network materials are not yet understood. A versatile multiscale simulation framework to model non-ideal (and thus large sized) MOF systems has been developed but a theoretical prediction of potential defects could not be achieved and thus a feedback into experimental design is still lacking.
Publications
- "Multiscale Modeling of the HKUST- 1/Poly(vinyl alcohol) Interface: From an Atomistic to a Coarse Graining Approach", J. Phys. Chem. C 2017, 121, 21491–21496
R. Semino, J. P. Dürholt, R. Schmid, G. Maurin
(See online at https://doi.org/10.1021/acs.jpcc.7b07090) - "Ab initio derived force fields for Zeolitic Imidazolate Frameworks: MOF-FF for ZIFs", J. Chem. Theory Comput. 2019, 15, 2420-2432
P. Dürholt, G. Fraux, F.X. Coudert, R. Schmid
(See online at https://doi.org/10.1021/acs.jctc.8b01041) - “Chemical Reactions at Isolated Single-Sites Inside Metal–Organic Frameworks”, Catal. Lett. 2018, 148, 2201–2222
Y. Wang, C. Wöll
(See online at https://doi.org/10.1007/s10562-018-2432-2) - “Defect Creation in Surface-Mounted Metal-Organic Framework Thin Films,” ACS Appl. Mater. Interf. 2020, 12, 2655-2661
Z. Wang, S. Henke, M. Paulus, A. Welle, Z. Y. Fan, K. Rodewald, B. Rieger, R. A. Fischer
(See online at https://doi.org/10.1021/acsami.9b18672) - “Defect- Engineering of Copper Paddle-Wheel based Metal-Organic Frameworks of Type NOTT-100: Implementing Truncated Linkers and Its Effect on Catalytic Properties”, ACS Appl. Mater. Interfaces 2020, 12, 37993–38002
Z. Fan, J. Wang, W. Wang, Z. Wang, Y. Wang, C. Wöll, M. Cokoja, R. A. Fischer
(See online at https://doi.org/10.1021/acsami.0c07249) - “Interplay of Electronic and Steric Effects to Yield Low-Temperature CO Oxidation at Metal Single Sites in Defect-Engineered HKUST-1”, Angew. Chem. Int. Ed. 2020, 59, 10514-10518
W. Wang, D. I. Sharapa, A. Chandresh, A. Nefedov, S. Heißler, L. Heinke, F. Studt, Y. Wang, C. Wöll
(See online at https://doi.org/10.1002/anie.202000385) - “Thermal Defect Engineering of Precious Group Metal-Organic Frameworks: Impact on the Catalytic Cyclopropanation Reaction”, Cat. Sci&Tech. 2020, 10, 8077-8085
W. R. Heinz, R. Junk, I. Aguirrezabal-Telleria, B. Bueken, H. Bunzen, T. Gölz, M. Cokoja, D. De Vos, R. A. Fischer
(See online at https://doi.org/10.1039/D0CY01479F) - “Thermal Defect-Engineering of Precious Group Metal-Organic Frameworks: A Case Study on Ru/Rh-HKUST-1 Analogues”, ACS Appl. Mater. Interfaces 2020, 12, 40635–40647
W. R. Heinz, I. Agirrezabal-Telleria, R. Junk, J. Berger, J. Wang, D. I. Sharapa, M. Gil- Calvo, I. Luz, M. Soukri, F. Studt, Y. Wang, C. Wöll, H. Bunzen, M. Drees and R. A. Fischer
(See online at https://doi.org/10.1021/acsami.0c10721) - “Defect engineering: an effective tool for enhancing the catalytic performance of copper-MOFs for the click reaction and the A3 coupling”, Cat. Sci & Tech. 2021
Z. Fan, Z. Wang, M. Cokoja, R. A. Fischer
(See online at https://doi.org/10.1039/D0CY01946A) - “Defect-Engineered Metal-Organic Frameworks: A Thorough Characterization of Active Sites Using CO as a Probe Molecule”, J. Phys Chem. C. 2021, 125, 593-601
J. Wang, W. Wang, Z. Fan, S. Chen, A. Nefedov, S. Heißler, R. A. Fischer, C. Wöll, Y. Wang
(See online at https://doi.org/10.1021/acs.jpcc.0c09738)
