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DOI: 10.1002/cctc.201801626
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Fe/Fe2O3@N-dopped Porous Carbon: A High-Performance
Catalyst for Selective Hydrogenation of Nitro Compounds
Ruirui Yun,*[a] Lirui Hong,[a] Wanjiao Ma,[a] Weiguo Jia,[a] Shoujie Liu,*[a] and Baishu Zheng*[b]
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Herein, we designed and prepared a novel Fe/Fe2O3-based
catalyst, in which a remarkable synergistic effect has been
revealed between Fe and Fe2O3 encapsulated in N-doping
porous carbon. The Fe-based catalysts were fabricated via
pyrolysis a mixture of MIL-101(Fe) and melamine. The catalyst
exhibits exceptionally high catalytic activity (TOFs up to
8898 hÀ 1 which is about 100 times higher than the similar kinds
of catalysts) and chemoselectivity for nitroarene reduction
under mild conditions.
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Introduction
In the past decades, much attention has been paid to
develop heteroatom decorated porous carbon materials which
considerably broadens their potential applications. Among
various possible dopants, nitrogen-containing nanostructured
carbon materials are potentially of great technological interest
for the development of a catalytic system.[8] It is widely
accepted that the nitrogen atoms in metal modified N-doping
carbon catalysts act as base sites which could increase the
performance of hydrogenation of nitro compounds.[9] Addition-
ally, to obtain efficient and stable metal-base catalysts, having
base metal nanoparticles (NPs) with small sizes stabilized inside
a stable porous matrix would be an ideal strategy. In the
previous studies, much more attention has been focused on
Zeolitic imidazolate frameworks (ZIFs),[10] which fabricated by
imidazole and metal ions can be pyrolyzed to obtain N-doping
porous carbon.[11] However, up to now, the less nitrogen
content of the N-doping porous carbon limits its application.
For this purpose, metal-organic frameworks (MOFs),[12] the
same as ZIFs, are a novel class of porous materials with
polyhedral cage, abundant carbon and high metal ion contents
and are expected to be good candidates as the precursor
template to design various porous nanostructured metal oxide
hybrid materials.[13] Therefore, a new strategy, which pyrolyze
the mixture of MOFs and N-contain organic ligands, to obtain
tolerant catalyst was sought that would minimize reaction times
and have high chemoselectivity.
Catalysis is a core field of material science due to their widely
application in modern chemistry.[1] Selectivity and catalyst
separation are major issue in heterogeneous catalysis.[2] In
particular, the chemoselective hydrogenation of functionalized
nitro compounds to amine is an industrially important trans-
formation, principally in the agrochemical, pigment and
pharmaceutical industries.[3] Achieving high selectivity along
with high conversion has emerged as the prime concern in
designing catalysts. Consequently, much more methods have
been applied to obtain highly efficient catalysts, such as doping
heteroatom and bimetallic synergistic effect.[4]
In terms of industrial applications, heterogeneous catalysts
instead of homogeneous ones attract more and more atten-
tions due to the ease of their separation and recycling.[5]
However, various metal catalysts based on noble metal-based
(for example, Pd, Pt, Au, Ru, etc.) are often not chemoselective.[6]
Therefore, the heterogeneous catalysts based upon earth-
abundant metal, such as Fe, Co, and Ni, have been devoted to
designing.[7] Although earth-abundant metals are low-cost,
sintering or leaching of them cause irreversible deactivation of
the catalysts under liquid phase conditions, so new strategies
have been designed to fabricate stable, high active, and
selective earth-abundant metal catalysts are very necessary.
The MIL-101 (Fe) was solvothermally synthesized based
upon Fe(NO3)3·6H2O and terephthalic acid in DMF solution. The
structure and phrase purity of MIL-101(Fe) have been confirmed
by powder X-ray diffraction (XRD) (Figure S1, ESI). The catalysts
Fe/Fe2O3@NnPC-T-X (n represent the ratio of MIL-101 (Fe) and
melamine, T represent pyrolysis temperature and x represent
[a] Prof. R. Yun, L. Hong, W. Ma, W. Jia, Dr. S. Liu
The Key Laboratory of Functional Molecular Solids
Ministry of Education
College of Chemistry and Materials Science
Anhui Normal University
Wuhu 241000 (P. R. China)
E-mail: ruirui58@ahnu.edu.cn
[b] Prof. Dr. B. Zheng
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pyrolysis time; n=0, 1, 2, 3, 4, 5, 6; T=600 C, 700 C, 800 C; x=
1 h, 2 h, 3 h) were prepared in sequential pyrolysis procedure in
an Ar atmosphere (Figure 1, see details in the ESI). Catalysts
optimization studies revealed a dependence on the three key
variables: (1) the ratio of MIL-101 (Fe) and melamine, (2) the
pyrolysis temperature, and (3) the time of pyrolysis. As Powder
X-ray diffraction patterns indicate the composition of the
products obtained at different temperature displays distinct
differences while the different ratio and time are not (Figure S2,
Key Laboratory of Theoretical Organic Chemistry and Function Molecule
Ministry of Education
Hunan Provincial Key Laboratory of Controllable Preparation and Functional
Application of Fine Polymers
School of Chemistry and Chemical Engineering
Hunan University of Science and Technology
Xiangtan 411201 (P. R. China)
E-mail: zbaishu@163.com
Supporting information for this article is available on the WWW under
ChemCatChem 2018, 10, 1–6
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© 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
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