Abstract
Metal-organic frameworks (MOFs) provide convenient systems for organizing high concentrations of single catalytic sites derived from metallic or oxo-metallic nodes. However, high-temperature processes cause agglomeration of these nodes, so that the single-site character and catalytic activity are lost. In this work, we present a simple nanocasting approach to provide a thermally stable secondary scaffold for MOF-based catalytic single sites, preventing their aggregation even after exposure to air at 600°C. We describe the nanocasting of NU-1000, a MOF with 3 nm channels and Lewis-acidic oxozirconium clusters, with silica. By condensing tetramethylorthosilicate within the NU-1000 pores via a vapor-phase HCl treatment, a silica layer is created on the inner walls of NU-1000. This silica layer provides anchoring sites for the oxozirconium clusters in NU-1000 after the organic linkers are removed at high temperatures. Differential pair distribution functions obtained from synchrotron X-ray scattering confirmed that isolated oxozirconium clusters are maintained in the heated nanocast materials. Pyridine adsorption experiments and a glucose isomerization reaction demonstrate that the clusters remain accessible to reagents and maintain their acidic character and catalytic activity even after the nanocast materials have been heated to 500-600°C in air. Density functional theory calculations show a correlation between the Lewis acidity of the oxozirconium clusters and their catalytic activity. The ability to produce MOF-derived materials that retain their catalytic properties after exposure to high temperatures makes nanocasting a useful technique for obtaining single-site catalysts suitable for high-temperature reactions.
| Original language | English |
|---|---|
| Pages (from-to) | 2739-2748 |
| Number of pages | 10 |
| Journal | Journal of the American Chemical Society |
| Volume | 138 |
| Issue number | 8 |
| DOIs | |
| Publication status | Published - Mar 2 2016 |
Fingerprint
ASJC Scopus subject areas
- Chemistry(all)
- Catalysis
- Biochemistry
- Colloid and Surface Chemistry
Cite this
Thermal Stabilization of Metal-Organic Framework-Derived Single-Site Catalytic Clusters through Nanocasting. / Malonzo, Camille D.; Shaker, Sammy M.; Ren, Limin; Prinslow, Steven D.; Platero-Prats, Ana E.; Gallington, Leighanne C.; Borycz, Joshua; Thompson, Anthony B.; Wang, Timothy C.; Farha, Omar K.; Hupp, Joseph T; Lu, Connie C.; Chapman, Karena W.; Myers, Jason C.; Penn, R. Lee; Gagliardi, Laura; Tsapatsis, Michael; Stein, Andreas.
In: Journal of the American Chemical Society, Vol. 138, No. 8, 02.03.2016, p. 2739-2748.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Thermal Stabilization of Metal-Organic Framework-Derived Single-Site Catalytic Clusters through Nanocasting
AU - Malonzo, Camille D.
AU - Shaker, Sammy M.
AU - Ren, Limin
AU - Prinslow, Steven D.
AU - Platero-Prats, Ana E.
AU - Gallington, Leighanne C.
AU - Borycz, Joshua
AU - Thompson, Anthony B.
AU - Wang, Timothy C.
AU - Farha, Omar K.
AU - Hupp, Joseph T
AU - Lu, Connie C.
AU - Chapman, Karena W.
AU - Myers, Jason C.
AU - Penn, R. Lee
AU - Gagliardi, Laura
AU - Tsapatsis, Michael
AU - Stein, Andreas
PY - 2016/3/2
Y1 - 2016/3/2
N2 - Metal-organic frameworks (MOFs) provide convenient systems for organizing high concentrations of single catalytic sites derived from metallic or oxo-metallic nodes. However, high-temperature processes cause agglomeration of these nodes, so that the single-site character and catalytic activity are lost. In this work, we present a simple nanocasting approach to provide a thermally stable secondary scaffold for MOF-based catalytic single sites, preventing their aggregation even after exposure to air at 600°C. We describe the nanocasting of NU-1000, a MOF with 3 nm channels and Lewis-acidic oxozirconium clusters, with silica. By condensing tetramethylorthosilicate within the NU-1000 pores via a vapor-phase HCl treatment, a silica layer is created on the inner walls of NU-1000. This silica layer provides anchoring sites for the oxozirconium clusters in NU-1000 after the organic linkers are removed at high temperatures. Differential pair distribution functions obtained from synchrotron X-ray scattering confirmed that isolated oxozirconium clusters are maintained in the heated nanocast materials. Pyridine adsorption experiments and a glucose isomerization reaction demonstrate that the clusters remain accessible to reagents and maintain their acidic character and catalytic activity even after the nanocast materials have been heated to 500-600°C in air. Density functional theory calculations show a correlation between the Lewis acidity of the oxozirconium clusters and their catalytic activity. The ability to produce MOF-derived materials that retain their catalytic properties after exposure to high temperatures makes nanocasting a useful technique for obtaining single-site catalysts suitable for high-temperature reactions.
AB - Metal-organic frameworks (MOFs) provide convenient systems for organizing high concentrations of single catalytic sites derived from metallic or oxo-metallic nodes. However, high-temperature processes cause agglomeration of these nodes, so that the single-site character and catalytic activity are lost. In this work, we present a simple nanocasting approach to provide a thermally stable secondary scaffold for MOF-based catalytic single sites, preventing their aggregation even after exposure to air at 600°C. We describe the nanocasting of NU-1000, a MOF with 3 nm channels and Lewis-acidic oxozirconium clusters, with silica. By condensing tetramethylorthosilicate within the NU-1000 pores via a vapor-phase HCl treatment, a silica layer is created on the inner walls of NU-1000. This silica layer provides anchoring sites for the oxozirconium clusters in NU-1000 after the organic linkers are removed at high temperatures. Differential pair distribution functions obtained from synchrotron X-ray scattering confirmed that isolated oxozirconium clusters are maintained in the heated nanocast materials. Pyridine adsorption experiments and a glucose isomerization reaction demonstrate that the clusters remain accessible to reagents and maintain their acidic character and catalytic activity even after the nanocast materials have been heated to 500-600°C in air. Density functional theory calculations show a correlation between the Lewis acidity of the oxozirconium clusters and their catalytic activity. The ability to produce MOF-derived materials that retain their catalytic properties after exposure to high temperatures makes nanocasting a useful technique for obtaining single-site catalysts suitable for high-temperature reactions.
UR - http://www.scopus.com/inward/record.url?scp=84960156654&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84960156654&partnerID=8YFLogxK
U2 - 10.1021/jacs.5b12688
DO - 10.1021/jacs.5b12688
M3 - Article
VL - 138
SP - 2739
EP - 2748
JO - Journal of the American Chemical Society
JF - Journal of the American Chemical Society
SN - 0002-7863
IS - 8
ER -