Challenges in the Synthesis of Metal-Organic Frameworks Jeffrey R. - - PowerPoint PPT Presentation
Challenges in the Synthesis of Metal-Organic Frameworks Jeffrey R. Long Departments of Chemistry and Chemical & Biomolecular Engineering University of California, Berkeley Materials Sciences Division, Lawrence Berkeley National Laboratory
Yaghi et al. Nature 2003, 423, 705 Kitagawa et al. Angew. Chem., Int. Ed. 2004, 43, 2334 Férey Chem. Soc. Rev. 2008, 37, 191
Requires that the MOF selectively adsorbs just one component of the mixture High surface area leads to a high working capacity for removing one component
An enormous number of structures are possible; most are not highly porous Impossible to predict conditions leading to pure, crystalline target structure
Solid powders dosed from hoppers with a precision of ±0.1 mg Delivery of solids and liquids to 96 reaction vials can be accomplished in ca. 2 h
Dinca, Dailly, Liu, Brown, Neumann, Long J. Am. Chem. Soc. 2006, 128, 16876 1) 70 °C, DMF/MeOH 2) MeOH soak 3) 150 °C, in vacuo One of the first MOFs shown to contain coordinatively-unsaturated metal sites
Different metals can require very different conditions often with mixed solvents
Sumida, Horike, Kaye, Herm, Queen, Brown, Grandjean, Long, Dailly, Long Chem. Sci. 2010, 1, 184
Low-cost benchtop NMR instrument Solvent (proton) relaxation times can afford pore size distribution information Enables rapid high-throughput evaluation of porosity of new materials
Chen, Mason, Bloch, Gygi, Long, Reimer Micropor. Mesopor. Mater. 2015, 205, 65
Strong correlation with Langmuir surface area, even for paramagnetic
Equilibrium adsorption measurements based upon mass spec analysis Can measure 28 samples in parallel for mixture including CO2, N2, H2O, O2, SO2 Mason, McDonald, Bae, Bachman, Sumida, Dutton, Kaye, Long, J. Am Chem. Soc. 2015, 137, 4787
At the critical radius, the free energy of stable crystal outweighs surface energy Expanded forms of classical nucleation theory include heterogeneous nucleation
Dubrovskii, Nucleation Theory and Growth of Nanostructures, NanoScience and Technology, DOI: 10.1007/978-3-642-39660-1_1
Some MOFs have been shown to form multiple products sequentially Cölfen, Mann Angew. Chem., Int. Ed. 2003, 42, 2350
Patterson, et al. J. Am. Chem. Soc. 2015, 137, 7322; Cubillas, et al. J. Phys. Chem. C. 2014, 118, 23092 O’Donnell, et al. J.Am. Chem. Soc. 2007, 129, 1578; Vistad, et al. Chem. Mater. 2003, 15, 8939
Brent, Anderson Angew. Chem. Int. Ed. 2008, 47, 5327
Height differences as a function of time can give structural information
John, Scherb, Shoaee, Anderson, Attfield, Bein Chem. Commun. 2009, 6294
Step heights and facets indicate layer-by-layer growth along the [111] direction
Crystals of Co2(dobdc) (Co-MOF-74) generally form as agglomerates of long rods
Rousseau, Handbook of Separation Process Technology, John Wiley and Sons: 1987, pp. 669-671
For equal volume, average time to site within MOF depends on aspect ratio
Plate morphology favors rapid transport and can enable use in membranes
These additives can influence many equilibria simultaneously Modulators such as terminal carboxylates often not incorporated in bulk We have little understanding of how this works
Bloch, Murray, Queen, Maximoff, Chavan, Bigi, Krishna, Peterson, Grandjean, Long, Smit, Bordiga, Brown, Long
Dietzel, Morita, Blom, Fjellvåg Angew. Chem., Int. Ed. 2005, 44, 6354 Rosi, Kim, Eddaoudi, Chen, O’Keeffe, Yaghi J. Am. Chem. Soc. 2005, 127, 1504 Caskey, Wong-Foy, Matzger J. Am. Chem. Soc. 2008, 130, 10870
Activated frameworks have Langmuir surface areas of 1280-2060 m2/g
Record high density of open metal coordination sites per unit mass or volume
Bloch, Queen, Krishna, Zadrozny, Brown, Long Science 2012, 335, 1606
Selectivity based upon interaction of π electrons with the cationic metal center Extremely high separation capacities can be achieved owing to the high density of metals
Despite many years of trying, we have failed to find conditions that form these MOFs
Challenges involve overly reducing metals or sluggish reaction kinetics
Lee, Isley, Dzubak, Verma, Stoneburner, Bloch, Reed, Hudson, Lin, Kim, Brown, Long, Neaton, Smit, Cramer, Truhlar, Gagliardi
First demonstration of two gas molecules binding to a metal center in a MOF
Runčevski, Kapelewski, Torres-Gavosto, Tarver, Brown, Long Chem. Commun. 2016, 52, 8251
MOFs with coordinatively-unsaturated metals that bind 2-4 gas molecules should
Pores with regular acute angles are not known for traditional adsorbents
Herm, Wiers, Mason, van Baten, Hudson, Zajdel, Brown, Masciocchi, Krishna, Long Science 2013, 340, 960
Enables shape-based separations, such as fractionation of hexane isomers
Could improve conversion with increase in yields for a given reactor volume Simulations indicate similar separation ability for isomers of pentane and heptane
Herm, Wiers, Mason, van Baten, Hudson, Zajdel, Brown, Masciocchi, Krishna, Long Science 2013, 340, 960
McDonald, Mason, Kong, Bloch, Gygi, Dani, Crocellà, Giordano, Odoh, Drisdell, Vlaisavljevich, Dzubak, Poloni, Schnell, Planas, Kyuho, Pascal, Prendergast, Neaton, Smit, Kortright, Gagliardi, Bordiga, Reimer, Long Nature 2015, 519, 303
McDonald, Mason, Kong, Bloch, Gygi, Dani, Crocellà, Giordano, Odoh, Drisdell, Vlaisavljevich, Dzubak, Poloni, Schnell, Planas, Kyuho, Pascal, Prendergast, Neaton, Smit, Kortright, Gagliardi, Bordiga, Reimer, Long Nature 2015, 519, 303
Allow a high separation capacity with small changes in temperature or pressure
Reed, Keitz, Oktawiec, Mason, Runcevski, Xiao, Darago, Crocella, Bordiga, Long Nature 2017, 550, 96
Thus far, cooperative adsorbents have been achieved only for CO2 and CO