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Cyclodextrin polymer networks decorated with subnanometer metal nanoparticles for high-performance low-temperature catalysis

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Science Advances  01 Nov 2019:
Vol. 5, no. 11, eaax6976
DOI: 10.1126/sciadv.aax6976
  • Fig. 1 CPN synthesized by a click reaction.

    (A) Synthesis of the CPN from per-(6-azido-6-deoxy)-β-cyclodextrins with 1,4-diethynylbenzene. (B) TEM images of the CPN. Inset: Selected area electron diffraction of the dashed black square. (C) Scanning electron microscopy image of the CPN. (D) Photo of the as-prepared CPN powder (photo credit: Tiefan Huang, KAUST).

  • Fig. 2 Synthesis and characterizations of PdNPs@CPN.

    (A) Wet chemistry procedure of metal NPs@CPN synthesis. (B) SEM image. (C and D) TEM images at different magnifications. Inset: Selected area electron diffraction of the dashed black square. (E and F) HAADF-STEM images at different magnifications. Inset: Size distribution of PdNPs in PdNPs@CPN. (G) EDS of PdNPs@CPN. (H) EDS mapping of composition elements Pd, C, N, and O, respectively.

  • Fig. 3 Morphology characterizations of various metal NPs@CPN.

    HAADF-STEM images of (A) AgNPs@CPN, (B) PtNPs@CPN, (C) AuNPs@CPN, and (D) RhNPs@CPN.

  • Fig. 4 Catalytic performance of PdNPs@CPN for 4-nitrophenol reduction.

    (A) UV-Vis spectra of 0.1 mM 4-nitrophenol (4-NP) aqueous solution before and after addition of NaBH4. Time-dependent UV-Vis spectra of the reduction of 4-NP (0.1 mM) in NaBH4 (10 mM) aqueous solution catalyzed by (B) CPN, (C) Pd black, and (D) PdNPs@CPN. Inset: Optical images of reaction mixtures at 0 and 3 min. (E) Recyclability of the PdNPs@CPN for seven cycles of 4-NP reduction reactions. (F) Time-dependent UV-Vis spectra of the reduction of 4-NP (0.1 mM) catalyzed by PdNPs@CPN with the addition of 1-adamantane-carboxylate sodium salt (ACNa).

  • Table 1 Catalytic performance of PdNPs@CPN in the hydrogenation reactions for various nitroarenes.
    Embedded Image

    *Gas chromatography–mass spectrometry result.

    †Reaction conditions: nitroarenes (2.3 mmol), PdNPs@CPN (0.25 mol %), H2O (4 ml), room temperature.

    ‡Without PdNPs@CPN.

    §Nitroarenes (1 mmol), PdNPs@CPN (0.25 mol %), and 50 ml of H2O/methanol (3:2) as the solvent.

    ║Pd/C as the catalyst.

    ¶Pt/alumina as the catalyst.

    Supplementary Materials

    • Supplementary material for this article is available at http://advances.sciencemag.org/cgi/content/full/5/11/eaax6976/DC1

      Section S1. Materials and methods

      Section S2. Characterization of CPN

      Section S3. Characterization of PdNPs@CPN

      Fig. S1. FT-IR spectra of β-cyclodextrin, per-(6-iodo-6-deoxy)-b-cyclodextrin, and per-(6-azido-6-deoxy)-β-cyclodextrins.

      Fig. S2. 1H NMR spectra of b-cyclodextrin, per-(6-iodo-6-deoxy)-b-cyclodextrin, and per-(6-azido-6-deoxy)-β-cyclodextrins in DMSO-d6.

      Fig. S3. 13C NMR spectra of b-cyclodextrin, per-(6-iodo-6-deoxy)-b-cyclodextrin, and per-(6-azido-6-deoxy)-β-cyclodextrins in DMSO-d6.

      Fig. S4. Photo of as-prepared CPN.

      Fig. S5. FT-IR spectra of 1,4-diethynylbenzene, per-(6-azido-6-deoxy)-β-cyclodextrins, and CPN.

      Fig. S6. Solid-state 13C CP/MAS NMR spectrum of CPN.

      Fig. S7. XPS survey spectrum of CPN.

      Fig. S8. High-resolution XPS spectra of CPN.

      Fig. S9. Molecular weight of each moiety in the CPN.

      Fig. S10. PXRD patterns of CPN.

      Fig. S11. TGA curve of β-cyclodextrin and CPN.

      Fig. S12. Photos of CPN impregnated with Pd2+.

      Fig. S13. Solid-state 13C CP/MAS NMR spectra of Pd(II)@CPN and PdNPs@CPN.

      Fig. S14. FT-IR spectra of Pd(II)@CPN and PdNPs@CPN.

      Fig. S15. High-resolution XPS spectra of CPN, Pd(II)@CPN, and PdNPs@CPN.

      Fig. S16. PXRD patterns of Pd(II)@CPN, PdNPs@CPN, Pd black, and Pd(OAc)2.

      Fig. S17. TEM images of PdNPs@CDP.

      Fig. S18. TEM images of unsupported PdNPs.

      Fig. S19. Photos of CPN impregnated with various metal ions and after reduction treatment.

      Fig. S20. TEM images of various metal NPs@CPN.

      Fig. S21. EDS mapping of various metal NPs@CPN.

      Fig. S22. Recyclability of the Pd/C for three cycles of 4-NP reduction reactions.

      Fig. S23. TEM image of PdNPs@CPN after seven reaction cycles.

      Table S1. Synthesis of CPN using different monomers and ratios.

      Table S2. Weight percent of respective metal in various metal NPs@CPN.

      Table S3. Catalytic activity test of PdNPs@CPN in the Suzuki-Miyaura coupling reaction.

      Table S4. Metal NPs supported on various substrates.

      References (4048)

    • Supplementary Materials

      This PDF file includes:

      • Section S1. Materials and methods
      • Section S2. Characterization of CPN
      • Section S3. Characterization of PdNPs@CPN
      • Fig. S1. FT-IR spectra of β-cyclodextrin, per-(6-iodo-6-deoxy)-β-cyclodextrin, and per-(6-azido-6-deoxy)-β-cyclodextrins.
      • Fig. S2. 1H NMR spectra of β-cyclodextrin, per-(6-iodo-6-deoxy)-β-cyclodextrin, and per-(6-azido-6-deoxy)-β-cyclodextrins in DMSO-d6.
      • Fig. S3. 13C NMR spectra of β-cyclodextrin, per-(6-iodo-6-deoxy)-β-cyclodextrin, and per-(6-azido-6-deoxy)-β-cyclodextrins in DMSO-d6.
      • Fig. S4. Photo of as-prepared CPN.
      • Fig. S5. FT-IR spectra of 1,4-diethynylbenzene, per-(6-azido-6-deoxy)-β-cyclodextrins, and CPN.
      • Fig. S6. Solid-state 13C CP/MAS NMR spectrum of CPN.
      • Fig. S7. XPS survey spectrum of CPN.
      • Fig. S8. High-resolution XPS spectra of CPN.
      • Fig. S9. Molecular weight of each moiety in the CPN.
      • Fig. S10. PXRD patterns of CPN.
      • Fig. S11. TGA curve of β-cyclodextrin and CPN.
      • Fig. S12. Photos of CPN impregnated with Pd2+.
      • Fig. S13. Solid-state 13C CP/MAS NMR spectra of Pd(II)@CPN and PdNPs@CPN.
      • Fig. S14. FT-IR spectra of Pd(II)@CPN and PdNPs@CPN.
      • Fig. S15. High-resolution XPS spectra of CPN, Pd(II)@CPN, and PdNPs@CPN.
      • Fig. S16. PXRD patterns of Pd(II)@CPN, PdNPs@CPN, Pd black, and Pd(OAc)2.
      • Fig. S17. TEM images of PdNPs@CDP.
      • Fig. S18. TEM images of unsupported PdNPs.
      • Fig. S19. Photos of CPN impregnated with various metal ions and after reduction treatment.
      • Fig. S20. TEM images of various metal NPs@CPN.
      • Fig. S21. EDS mapping of various metal NPs@CPN.
      • Fig. S22. Recyclability of the Pd/C for three cycles of 4-NP reduction reactions.
      • Fig. S23. TEM image of PdNPs@CPN after seven reaction cycles.
      • Table S1. Synthesis of CPN using different monomers and ratios.
      • Table S2. Weight percent of respective metal in various metal NPs@CPN.
      • Table S3. Catalytic activity test of PdNPs@CPN in the Suzuki-Miyaura coupling reaction.
      • Table S4. Metal NPs supported on various substrates.
      • References (4048)

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