Cu-Based Metal–Organic Framework Nanosheets
Synthesized via a Three-Layer Bottom-Up Method
for the Catalytic Conversion of S‑Nitrosoglutathione
to Nitric Oxide
Version 2 2021-12-29, 12:33Version 2 2021-12-29, 12:33
Version 1 2021-12-28, 21:43Version 1 2021-12-28, 21:43
journal contribution
posted on 2021-12-29, 12:33authored byJonathan
E. Thai, Robert R. Tuttle, Jacob DeRoo, Jamie Cuchiaro, Melissa M. Reynolds
Metal–organic
framework nanosheets (MOFNs) are promising
materials for heterogeneous catalysis systems where active metal sites
are positioned on particle exterior surfaces. The hypothesis that
intrapore metal sites are active for catalysis has been disproven
for certain systems, and therefore the synthesis of MOF particles
with increased external surface area and density of metal active sites
is needed. MOFNs provide an increased proportion of metal sites accessible
to substrates that experience limited or no diffusion into MOF pores
compared to MOF particles with other morphologies such as octahedra.
However, developing synthetic methods to generate a variety of MOFNs
remains an experimental challenge, particularly for water-stable materials.
Herein, we use a three-layer method to synthesize the nanosheet particles
of a new MOF, CuBDTri (where H2BDTri = 1,4-di(1H-1,2,3-triazol-5-yl)benzene). Scanning electron microscopy
(SEM), powder X-ray diffraction (pXRD), Brunauer–Emmett–Teller
(BET) analysis, inductively coupled plasma atomic emission spectroscopy
(ICP-AES), and acid digestion with time-of-flight mass spectrometry
(TOF-MS) were used to characterize the newly synthesized CuBDTri nanosheets.
Both the synthetic method and linker identity were shown to impact
the anisotropic growth of MOF particles with nanosheet morphologies.
Importantly, this is the first report of using the three-layer method
to synthesize MOFNs with Cu–N linkages, meaning that the three-layer
method is (i) more broadly applicable than previously known (having
only been used previously to synthesize nanosheets with Cu-oxo linkages)
and (ii) can be used to synthesize water-stable Cu-MOFNs in situ (a
key result, given MOFs with Cu-oxo linkages usually exhibit poor water
stability). CuBDTri nanosheets are also more catalytically active
on a per-total-Cu-atom basis for a standardized test reaction (nitric
oxide (NO) generation from S-nitrosoglutathione (GSNO))
than previously studied octahedral particles of the MOF CuBTTri (where
H3BTTri = 1,3,5-tris(1H-1,2,3-triazol-5-yl)benzene),
supporting the hypothesis that MOFNs are superior to particles with
other morphologies for reactions where catalytic activity is limited
to particle exterior surfaces (such as the NO generation reaction).