Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Gel-Based Morphological Design of Zirconium Metal-organic Frameworks   The ability of metal-organic frameworks (MOFs) to gelate under specific
synthetic conditions opens up new opportunities in the preparation and shaping
of hierarchically porous MOF monoliths, which could be directly implemented for
catalytic and adsorptive applications. In this work, we present the first
examples of xero- or aerogel monoliths consisting solely of nanoparticles of
several prototypical Zr4+-based MOFs: UiO-66-X (X = H, NH2, NO2, (OH)2),
UiO-67, MOF-801, MOF-808 and NU-1000. High reactant and water concentrations
during synthesis were observed to induce the formation of gels, which were
converted to monolithic materials by drying in air or supercritical CO2.
Electron microscopy, combined with N2 physisorption experiments, was used to
show that an irregular nanoparticle packing leads to pure MOF monoliths with
hierarchical pore systems, featuring both intraparticle micropores and
interparticle mesopores. Finally, UiO-66 gels were shaped into monolithic
spheres of 600 micrometer diameter using an oil-drop method, creating promising
candidates for packed-bed catalytic or adsorptive applications, where
hierarchical pore systems can greatly mitigate mass transfer limitations.

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The categories of this paper are: adap-org
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The categories of this paper are: patt-sol
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The categories of this paper are: bayes-an
34
The categories of this paper are: chem-ph
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The categories of this paper are: nucl-ex
14
The categories of this paper are: math-ph
31
The categories of this paper are: ao-sci
36
The categories of this paper are: cmp-lg
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The categories of this paper are: nlin
35
The categories of this paper are: mtrl-th
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The categories of this paper are: cs
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The categories of this paper are: hep-th
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The categories of this paper are: chao-dyn
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The categories of this paper are: acc-phys
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The categories of this paper are: nucl-th
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The categories of this paper are: atom-ph