1
|
Heaney MP, Johnson HM, Knapp JG, Bang S, Seifert S, Yaw NS, Li J, Farha OK, Zhang Q, Moreau LM. Uranyl uptake into metal-organic frameworks: a detailed X-ray structural analysis. Dalton Trans 2024; 53:5495-5506. [PMID: 38415508 DOI: 10.1039/d3dt04284g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/29/2024]
Abstract
Metal-organic frameworks (MOF) are a subclass of porous framework materials that have been used for a wide variety of applications in sensing, catalysis, and remediation. Among these myriad applications is their remarkable ability to capture substances in a variety of environments ranging from benign to extreme. Among the most common and problematic substances found throughout the world's oceans and water supplies is [UO2]2+, a common mobile ion of uranium, which is found both naturally and as a result of anthropogenic activities, leading to problematic environmental contamination. While some MOFs possess high capability for the uptake of [UO2]2+, many more of the thousands of MOFs and their modifications that have been produced over the years have yet to be studied for their ability to uptake [UO2]2+. However, studying the thousands of MOFs and their modifications presents an incredibly difficult task. As such, a way to narrow down the numbers seems imperative. Herein, we evaluate the binding behaviors as well as identify the specific binding sites of [UO2]2+ incorporated into six different Zr MOFs to elucidate specific features that improve [UO2]2+ uptake. In doing so, we also present a method for the determination and verification of these binding sites by Anomalous wide-angle X-ray scattering, X-ray fluorescence, and X-ray absorption spectroscopy. This research not only presents a way for future research into the uptake of [UO2]2+ into MOFs to be conducted but also a means to evaluate MOFs more generally for the uptake of other compounds to be applied for environmental remediation and improvement of ecosystems globally.
Collapse
Affiliation(s)
- Matthew P Heaney
- Department of Chemistry, Washington State University, Pullman, WA, 99164 USA.
| | - Hannah M Johnson
- Department of Chemistry, Washington State University, Pullman, WA, 99164 USA.
| | - Julia G Knapp
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208-3113, USA
| | - Shinhyo Bang
- Department of Chemistry, Washington State University, Pullman, WA, 99164 USA.
| | - Soenke Seifert
- X-ray sciences Division, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - Natalie S Yaw
- Department of Chemistry, Washington State University, Pullman, WA, 99164 USA.
| | - Jiahong Li
- Department of Chemistry, Washington State University, Pullman, WA, 99164 USA.
| | - Omar K Farha
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208-3113, USA
| | - Qiang Zhang
- Department of Chemistry, Washington State University, Pullman, WA, 99164 USA.
| | - Liane M Moreau
- Department of Chemistry, Washington State University, Pullman, WA, 99164 USA.
| |
Collapse
|
2
|
Yang D, Gates BC. Characterization, Structure, and Reactivity of Hydroxyl Groups on Metal-Oxide Cluster Nodes of Metal-Organic Frameworks: Structural Diversity and Keys to Reactivity and Catalysis. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024; 36:e2305611. [PMID: 37660323 DOI: 10.1002/adma.202305611] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Revised: 08/22/2023] [Indexed: 09/05/2023]
Abstract
Among the most stable metal-organic frameworks (MOFs) are those incorporating nodes that are metal oxide clusters with frames such as Zr6 O8 . This review is a summary of the structure, bonding, and reactivity of MOF node hydroxyl groups, emphasizing those bonded to nodes containing aluminum and zirconium ions. Hydroxyl groups are often present on these nodes, sometimes balancing the charges of the metal ions. They arise during MOF syntheses in aqueous media or in post-synthesis treatments. They are identified with infrared and 1 H nuclear magnetic resonance spectroscopies and characterized by their reactivities with polar compounds such as alcohols. Terminal OH, paired µ2 -OH, and aqua groups on nodes are catalytic sites in numerous reactions. Relatively unreactive hydroxyl groups (such as isolated µ2 -OH groups) may replace reactive groups and inhibit catalysis; some node hydroxyl groups (e.g., µ3 -OH) are mere spectators in catalysis. There are similarities between MOF node hydroxyl groups and those on the surfaces of bulk metal oxides, zeolites, and enzymes, but the comparisons are mostly inexact, and much remains to be understood about MOF node hydroxyl group chemistry. It is posited that understanding and controlling this chemistry will lead to tailored MOFs and improved adsorbents and catalysts.
Collapse
Affiliation(s)
- Dong Yang
- Department of Chemical Engineering, University of California, Davis, CA, 95616, USA
| | - Bruce C Gates
- Department of Chemical Engineering, University of California, Davis, CA, 95616, USA
| |
Collapse
|
3
|
Heterogenized Molecular Rhodium Phosphine Catalysts within Metal–Organic Frameworks for Alkene Hydroformylation. ACS Catal 2023. [DOI: 10.1021/acscatal.3c00398] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/14/2023]
|
4
|
Ultrasmall amorphous zirconia nanoparticles catalyse polyolefin hydrogenolysis. Nat Catal 2023. [DOI: 10.1038/s41929-023-00910-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
Abstract
AbstractCarbon–carbon bond cleavage reactions, adapted to deconstruct aliphatic hydrocarbon polymers and recover the intrinsic energy and carbon value in plastic waste, have typically been catalysed by metal nanoparticles or air-sensitive organometallics. Metal oxides that serve as supports for these catalysts are typically considered to be inert. Here we show that Earth-abundant, non-reducible zirconia catalyses the hydrogenolysis of polyolefins with activity rivalling that of precious metal nanoparticles. To harness this unusual reactivity, our catalytic architecture localizes ultrasmall amorphous zirconia nanoparticles between two fused platelets of mesoporous silica. Macromolecules translocate from bulk through radial mesopores to the highly active zirconia particles, where the chains undergo selective hydrogenolytic cleavage into a narrow, C18-centred distribution. Calculations indicated that C–H bond heterolysis across a Zr–O bond of a Zr(O)2 adatom model for unsaturated surface sites gives a zirconium hydrocarbyl, which cleaves a C–C bond via β-alkyl elimination.
Collapse
|
5
|
Melillo A, Franconetti A, Alvaro M, Ferrer B, Garcia H. Metal Nodes of Metal-Organic Frameworks can Activate Molecular Hydrogen. Chemistry 2023; 29:e202202625. [PMID: 36152311 PMCID: PMC10100435 DOI: 10.1002/chem.202202625] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Indexed: 01/04/2023]
Abstract
Hydrogenation of multiple bonds are among the most general and important organic reactions. Typical heterogeneous catalysts are based on transition metal nanoparticles, including noble metals. Data are presented here showing that metal nodes of MIL-101(Cr) and UiO-66 in the absence of occluded metal nanoparticles can promote hydrogenation of polarized X=Y double bonds of nitro and carbonyl groups. The catalytic activity is a function of the composition of the metal node and the organic linker. It is proposed that the reaction mechanism is based on the operation of frustrated Lewis acid/base pairs.
Collapse
Affiliation(s)
- Arianna Melillo
- Departamento de Química, Universitat Politècnica de València, Camino de Vera s/n, 46022, Valencia, Spain.,Insituto Universitario de Tecnologia Química, Consejo Superior de Investigaciones Científicas-Universitat Politècnica de València, av. De los Naranjos s/n, 46022, Valencia, Spain
| | - Antonio Franconetti
- CIC BioGUNE, Bizkaia Science and Technology Park, Building 800, 48160, Derio, Bizkaia, Spain
| | - Mercedes Alvaro
- Departamento de Química, Universitat Politècnica de València, Camino de Vera s/n, 46022, Valencia, Spain
| | - Belen Ferrer
- Departamento de Química, Universitat Politècnica de València, Camino de Vera s/n, 46022, Valencia, Spain
| | - Hermenegildo Garcia
- Departamento de Química, Universitat Politècnica de València, Camino de Vera s/n, 46022, Valencia, Spain.,Insituto Universitario de Tecnologia Química, Consejo Superior de Investigaciones Científicas-Universitat Politècnica de València, av. De los Naranjos s/n, 46022, Valencia, Spain
| |
Collapse
|
6
|
MOFs with bridging or terminal hydroxo ligands: Applications in adsorption, catalysis, and functionalization. Coord Chem Rev 2023. [DOI: 10.1016/j.ccr.2022.214912] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
|
7
|
Pan Y, Sanati S, Nadafan M, Abazari R, Gao J, Kirillov AM. Postsynthetic Modification of NU-1000 for Designing a Polyoxometalate-Containing Nanocomposite with Enhanced Third-Order Nonlinear Optical Performance. Inorg Chem 2022; 61:18873-18882. [PMID: 36375112 PMCID: PMC9775467 DOI: 10.1021/acs.inorgchem.2c02709] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
For the advancement of laser technologies and optical engineering, various types of new inorganic and organic materials are emerging. Metal-organic frameworks (MOFs) reveal a promising use in nonlinear optics, given the presence of organic linkers, metal cluster nodes, and possible delocalization of π-electron systems. These properties can be further enhanced by the inclusion of solely inorganic materials such as polyoxometalates as prospective low-cost electron-acceptor species. In this study, a novel hybrid nanocomposite, namely, SiW12@NU-1000 composed of SiW12 (H4SiW12O40) and Zr-based MOF (NU-1000), was assembled, completely characterized, and thoroughly investigated in terms of its nonlinear optical (NLO) performance. The third-order NLO behavior of the developed system was assessed by Z-scan measurements using a 532 nm laser. The effect of two-photon absorption and self-focusing was significant in both NU-1000 and SiW12@NU-1000. Experimental studies suggested a much superior NLO performance of SiW12@NU-1000 if compared to that of NU-1000, which can be assigned to the charge-energy transfer between SiW12 and NU-1000. Negligible light scattering, good stability, and facile postsynthetic fabrication method can promote the applicability of the SiW12@NU-1000 nanocomposite for various optoelectronic purposes. This research may thus open new horizons to improve and enhance the NLO performance of MOF-based materials through π-electron delocalization and compositing metal-organic networks with inorganic molecules as electron acceptors, paving the way for the generation of novel types of hybrid materials for prospective NLO applications.
Collapse
Affiliation(s)
- Yangdan Pan
- The
Key Laboratory of Advanced Textile Materials and Manufacturing Technology
of Ministry of Education, National Engineering Lab for Textile Fiber
Materials and Processing Technology, School of Materials Science and
Engineering, Zhejiang Sci-Tech University, Hangzhou310018, China
| | - Soheila Sanati
- Department
of Chemistry, Faculty of Science, University
of Maragheh, 55181-83111Maragheh, Iran
| | - Marzieh Nadafan
- Department
of Physics, Shahid Rajaee Teacher Training
University, 16788-15811Tehran, Iran
| | - Reza Abazari
- Department
of Chemistry, Faculty of Science, University
of Maragheh, 55181-83111Maragheh, Iran,
| | - Junkuo Gao
- The
Key Laboratory of Advanced Textile Materials and Manufacturing Technology
of Ministry of Education, National Engineering Lab for Textile Fiber
Materials and Processing Technology, School of Materials Science and
Engineering, Zhejiang Sci-Tech University, Hangzhou310018, China,
| | - Alexander M. Kirillov
- Centro
de Química Estrutural, Institute of Molecular Sciences, Departamento
de Engenharia Química, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001Lisbon, Portugal,
| |
Collapse
|
8
|
Hicks KE, Wolek ATY, Farha OK, Notestein JM. The Dependence of Olefin Hydrogenation and Isomerization Rates on Zirconium Metal–Organic Framework Structure. ACS Catal 2022. [DOI: 10.1021/acscatal.2c04303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Kenton E. Hicks
- Department of Chemistry and International Institute of Nanotechnology, Northwestern University, 2145 Sheridan Road, Evanston, Illinois60208, United States
| | - Andrew T. Y. Wolek
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, Illinois60208, United States
| | - Omar K. Farha
- Department of Chemistry and International Institute of Nanotechnology, Northwestern University, 2145 Sheridan Road, Evanston, Illinois60208, United States
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, Illinois60208, United States
| | - Justin M. Notestein
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, Illinois60208, United States
| |
Collapse
|
9
|
Xiao Y, Han L, Tang J, Tian L, Zhang Z, Zhang L, Yang D, Qiao X. Fabricating defect-rich metal-organic frameworks via mixed linker-induced crystal transformation. Chem Commun (Camb) 2022; 58:7265-7268. [PMID: 35674189 DOI: 10.1039/d2cc00923d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Defect-rich hcp UiO-66-NO2 was synthesized via mixed linker-induced crystal transformation from fcu UiO-66-NO2/NH2. The defect concentration and porosity of hcp UiO-66-NO2 can be fine-tuned by varying the BDC-NH2/BDC-NO2 ratio, which in turn endowed hcp UiO-66-NO2 with superior catalytic performance in the ring-opening reaction of epoxides with alcohols.
Collapse
Affiliation(s)
- Yue Xiao
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemical Engineering, Nanjing Tech University, Nanjing 211816, China.
| | - Lu Han
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemical Engineering, Nanjing Tech University, Nanjing 211816, China.
| | - Jihai Tang
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemical Engineering, Nanjing Tech University, Nanjing 211816, China.
| | - Lifang Tian
- Institute of Advanced Synthesis (IAS), School of Chemistry and Molecular Engineering, Nanjing Tech University, Nanjing 211816, China
| | - Zhuxiu Zhang
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemical Engineering, Nanjing Tech University, Nanjing 211816, China.
| | - Lixiong Zhang
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemical Engineering, Nanjing Tech University, Nanjing 211816, China.
| | - Dong Yang
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemical Engineering, Nanjing Tech University, Nanjing 211816, China.
| | - Xu Qiao
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemical Engineering, Nanjing Tech University, Nanjing 211816, China.
| |
Collapse
|
10
|
Wu J, Li X, Shi Z, He C. Single‐crystal‐to‐single‐crystal transformation and alcohols enantioseparation of homochiral Ir(III)‐metallohelix‐based porous molecular crystal. Eur J Inorg Chem 2022. [DOI: 10.1002/ejic.202200351] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Jinguo Wu
- Dalian University of Technology State Key Laboratory of Fine Chemicals CHINA
| | - Xuezhao Li
- Dalian University of Technology Zhang Dayu College of Chemistry CHINA
| | - Zhuolin Shi
- Dalian University of Technology State Key Laboratory of Fine Chemicals CHINA
| | - Cheng He
- Dalian University of Technology Linggong Road 2 116024 Dalian CHINA
| |
Collapse
|
11
|
Wu Y, Wang X, Kirlikovali KO, Gong X, Atilgan A, Ma K, Schweitzer NM, Gianneschi NC, Li Z, Zhang X, Farha OK. Catalytic Degradation of Polyethylene Terephthalate Using a Phase-Transitional Zirconium-Based Metal-Organic Framework. Angew Chem Int Ed Engl 2022; 61:e202117528. [PMID: 35353429 DOI: 10.1002/anie.202117528] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Indexed: 11/10/2022]
Abstract
Polyethylene terephthalate (PET) is utilized as one of the most popular consumer plastics worldwide, but difficulties associated with recycling PET have generated a severe environmental crisis with most PET ending its lifecycle in landfills. We report that zirconium-based metal-organic framework (Zr-MOF) UiO-66 deconstructs waste PET into the building blocks terephthalic acid (TA) and mono-methyl terephthalate (MMT) within 24 hours at 260 °C (total yield of 98 % under 1 atm H2 and 81 % under 1 atm Ar). Extensive structural characterization studies reveal that during the degradation process, UiO-66 undergoes an intriguing transformation into MIL-140A, which is another Zr-MOF that shows good catalytic activity toward PET degradation under similar reaction conditions. These results illustrate the diversity of applications for Zr-MOFs and establish MOFs as a new class of polymer degradation catalysts with the potential to address long-standing challenges associated with plastic waste.
Collapse
Affiliation(s)
- Yufang Wu
- School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou, Guangdong, 510640, P. R. China.,Department of Chemistry and International Institute for Nanotechnology, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208, USA
| | - Xingjie Wang
- Department of Chemistry and International Institute for Nanotechnology, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208, USA
| | - Kent O Kirlikovali
- Department of Chemistry and International Institute for Nanotechnology, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208, USA
| | - Xinyi Gong
- Department of Chemistry and International Institute for Nanotechnology, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208, USA
| | - Ahmet Atilgan
- Department of Chemistry and International Institute for Nanotechnology, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208, USA
| | - Kaikai Ma
- Department of Chemistry and International Institute for Nanotechnology, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208, USA
| | - Neil M Schweitzer
- Department of Chemical and Biological Engineering, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208, USA
| | - Nathan C Gianneschi
- Department of Chemistry and International Institute for Nanotechnology, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208, USA.,Department of Biomedical Engineering, Materials Science & Engineering, Pharmacology, Simpson-Querrey Institute, Chemistry of Life Processes Institute, Lurie Cancer Center, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208, USA
| | - Zhong Li
- School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou, Guangdong, 510640, P. R. China
| | - Xuan Zhang
- Department of Chemistry and International Institute for Nanotechnology, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208, USA
| | - Omar K Farha
- Department of Chemistry and International Institute for Nanotechnology, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208, USA.,Department of Chemical and Biological Engineering, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208, USA
| |
Collapse
|
12
|
Vlasenko ES, Nikovskiy IA, Nelyubina YV, Korlyukov AA, Novikov VV. Metal–organic framework ZIF-8 loaded with rhodium nanoparticles as a catalyst for hydroformylation. MENDELEEV COMMUNICATIONS 2022. [DOI: 10.1016/j.mencom.2022.05.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
|
13
|
Wu Y, Wang X, Kirlikovali KO, Gong X, Atilgan A, Ma K, Schweitzer NM, Gianneschi NC, Li Z, Zhang X, Farha OK. Catalytic Degradation of Polyethylene Terephthalate Using a Phase‐Transitional Zirconium‐Based Metal–Organic Framework. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202117528] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Yufang Wu
- School of Chemistry and Chemical Engineering South China University of Technology Guangzhou Guangdong 510640 P. R. China
- Department of Chemistry and International Institute for Nanotechnology Northwestern University 2145 Sheridan Road Evanston IL 60208 USA
| | - Xingjie Wang
- Department of Chemistry and International Institute for Nanotechnology Northwestern University 2145 Sheridan Road Evanston IL 60208 USA
| | - Kent O. Kirlikovali
- Department of Chemistry and International Institute for Nanotechnology Northwestern University 2145 Sheridan Road Evanston IL 60208 USA
| | - Xinyi Gong
- Department of Chemistry and International Institute for Nanotechnology Northwestern University 2145 Sheridan Road Evanston IL 60208 USA
| | - Ahmet Atilgan
- Department of Chemistry and International Institute for Nanotechnology Northwestern University 2145 Sheridan Road Evanston IL 60208 USA
| | - Kaikai Ma
- Department of Chemistry and International Institute for Nanotechnology Northwestern University 2145 Sheridan Road Evanston IL 60208 USA
| | - Neil M. Schweitzer
- Department of Chemical and Biological Engineering Northwestern University 2145 Sheridan Road Evanston IL 60208 USA
| | - Nathan C. Gianneschi
- Department of Chemistry and International Institute for Nanotechnology Northwestern University 2145 Sheridan Road Evanston IL 60208 USA
- Department of Biomedical Engineering, Materials Science & Engineering, Pharmacology Simpson-Querrey Institute Chemistry of Life Processes Institute Lurie Cancer Center Northwestern University 2145 Sheridan Road Evanston IL 60208 USA
| | - Zhong Li
- School of Chemistry and Chemical Engineering South China University of Technology Guangzhou Guangdong 510640 P. R. China
| | - Xuan Zhang
- Department of Chemistry and International Institute for Nanotechnology Northwestern University 2145 Sheridan Road Evanston IL 60208 USA
| | - Omar K. Farha
- Department of Chemistry and International Institute for Nanotechnology Northwestern University 2145 Sheridan Road Evanston IL 60208 USA
- Department of Chemical and Biological Engineering Northwestern University 2145 Sheridan Road Evanston IL 60208 USA
| |
Collapse
|
14
|
Affiliation(s)
- Divakar R. Aireddy
- Department of Chemical Engineering, Louisiana State University, Baton Rouge, Louisiana 70803, United States
| | - Kunlun Ding
- Department of Chemical Engineering, Louisiana State University, Baton Rouge, Louisiana 70803, United States
| |
Collapse
|
15
|
Yang D, Gates BC. Elucidating and Tuning Catalytic Sites on Zirconium- and Aluminum-Containing Nodes of Stable Metal-Organic Frameworks. Acc Chem Res 2021; 54:1982-1991. [PMID: 33843190 DOI: 10.1021/acs.accounts.1c00029] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
ConspectusMetal-organic frameworks (MOFs) are a huge, rapidly growing class of crystalline, porous materials that consist of inorganic nodes linked by organic struts. Offering the advantages of thermal stability combined with high densities of accessible reactive sites, some MOFs are good candidate materials for applications in catalysis and separations. Such MOFs include those with nodes that are metal oxide clusters (e.g., Zr6O8, Hf6O8, and Zr12O22) and long rods (e.g., [Al(OH)]n). These nanostructured metal oxides are often compared with bulk metal oxides, but they are in essence different because their structures are not the same and because the MOFs have a high degree of uniformity, offering the prospect of a deep understanding of reactivity that is barely attainable for most bulk metal oxides because of their surface heterogeneity. This prospect is being realized as it has become evident that adventitious components on MOF node surfaces, besides the linkers, are crucial. These ligands arise from modulators, solvents, or products of solvent decomposition in MOF synthesis solutions, and because they are minor components that are often irregularly placed on defects, they may not show up in X-ray diffraction (XRD) crystal structures. Hydroxyl groups on the nodes (like those on bulk metal oxides) are regarded as native functional groups arising from solvent water, but they may barely be present initially, with common ligands instead being formate and acetate formed from modulators formic acid and acetic acid. (Formate also arises from the decomposition of dimethylformamide (DMF) solvent.) Replacement and control of the node ligands is facilitated by postsynthesis reactions (e.g., with alcohols or aqueous HCl/H2SO4 solutions) or as a result of high-temperature decomposition. In catalysis, adventitious node ligands can be (a) reaction inhibitors that block active sites on the nodes (e.g., formate blocking Zr, Hf, or Al Lewis acid sites); (b) reaction intermediates (e.g., ethoxy in ethanol dehydration); or (c) active sites themselves (e.g., terminal OH groups in tert-butyl alcohol (TBA) dehydration). Surprisingly, in view of the catalytic importance of such ligands on bulk metal oxides, their subtle chemistry on MOF nodes is only recently being determined. We describe (1) methods for identifying and quantifying node ligands (especially by IR spectroscopy and by 1H NMR spectroscopy of MOFs digested in NaOH/D2O solutions); (2) node ligand surface chemistry expressed as reaction networks; (3) catalysis, with mechanisms and energetics determined by density functional theory (DFT) and spectroscopy; and (4) MOF unzipping by reactions of linker carboxylate ligands with reactants such as alcohols that break node-linker bonds, a cause of catalyst deactivation and also an indicator of node-linker bond strength and MOF stability.
Collapse
Affiliation(s)
- Dong Yang
- Department of Chemical Engineering, University of California, Davis, California 95616, United States
- College of Chemical Engineering, State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing, Jiangsu 21000, China
| | - Bruce C. Gates
- Department of Chemical Engineering, University of California, Davis, California 95616, United States
| |
Collapse
|