posted on 2020-03-05, 12:33authored byJavier Fonseca, Sunho Choi
Hierarchically porous materials with
high stability and tailorable
pore characters have potential for mass transfer applications, including
bulky molecule capture and separation, heterogeneous catalysis, and
drug delivery. The scope of functionalities can be notably broadened
by employing metal–organic framework (MOF) sheets with tunable
thickness as giant molecular building blocks for self-assembly into
hierarchical supramolecular porous coordination materials. However,
synthesizing MOF sheets with controllable bulkiness has proved challenging
for scientists. We present a rational yet unprecedented bottom-up
strategy to prepare a novel two-dimensional MOF sheet [Zn(BPDI)(Py)2] (BPDI = N,N′-bis(glycinyl)pyromellitic
diimide; Py = pyridine) with unusual and highly desired tunable thickness.
These sheets self-organize into a unique three-dimensional supramolecular
coordination material (NEU-1) with tailorable porosity. To assess
its technological relevance, NEU-1c is tested as a support of amine
sorbent for CO2 capture. Multichannel porous NEU-1c solves
the conventional trade-off suffered by supported amine carbon dioxide
adsorbents between increasing amine content and decreasing access
to amine sites. Our synthesis process opens the door to novel MOF
nanosheets and unique hierarchical supramolecular porous materials
with tailorable porosity.