A Reusable Mesoporous Nickel Nanocomposite Catalyst for the Selective Hydrogenation of Nitroarenes in the Presence of Sensitive Functional Groups

Article abstract of DOI:10.1002/cctc.201600391

The synthesis of aromatic amines from nitroarenes through hydrogenation is an industrially and academically important reaction. In addition, the employment of base metal catalysts in reactions that are preferentially mediated by rare noble metals is a desirable aim in catalysis and an attractive element-conservation strategy. Especially appealing is the observation of novel selectivity patterns with such inexpensive metal catalysts. Herein, we report a novel mesostructured Ni nanocomposite catalyst. It is the first example of a reusable Ni catalyst that is able to hydrogenate nitroarenes selectively to anilines in the presence of highly sensitive functional groups such as C=C bonds and nitrile, aldehyde, and iodo substituents.

Full text of DOI:10.1002/cctc.201600391

DOI: 10.1002/cctc.201600391
Communications
A Reusable Mesoporous Nickel Nanocomposite Catalyst
for the Selective Hydrogenation of Nitroarenes in the
Presence of Sensitive Functional Groups
Gabriela Hahn, Julia-Katharina Ewert, Christine Denner, Dominic Tilgner, and Rhett Kempe*[a]
The synthesis of aromatic amines from nitroarenes through hy-
drogenation is an industrially and academically important reac-
tion. In addition, the employment of base metal catalysts in re-
actions that are preferentially mediated by rare noble metals is
a desirable aim in catalysis and an attractive element-conserva-
tion strategy. Especially appealing is the observation of novel
selectivity patterns with such inexpensive metal catalysts.
Herein, we report a novel mesostructured Ni nanocomposite
catalyst. It is the first example of a reusable Ni catalyst that is
able to hydrogenate nitroarenes selectively to anilines in the
presence of highly sensitive functional groups such as C=C
bonds and nitrile, aldehyde, and iodo substituents.
thus another attractive alternative to existing noble-metal cata-
lysts. To the best of our knowledge, recycling[10] and the toler-
ance towards sensitive functional groups have not yet been
demonstrated for heterogeneous nickel catalysts able to hy-
drogenate nitroarenes efficiently.[11,12] The selectivity of our
nickel catalyst is comparable to those of some state-of-the-art
catalysts, such as the aforementioned cobalt and iron catalysts
developed by Beller and co-workers.[6,7] We recently developed
a novel class of heterogeneous M@SiCN nanocomposite cata-
lysts.[13,14] The silicon carbonitride (SiCN) support is thermally
very robust, chemically inert, and attractive for generating
rather small metal nanoparticles in such supports.[15] In addi-
tion, we introduced strategies to mesostructure SiCN[16–18] and
became interested in combining both approaches to synthe-
size highly active and selective base-metal catalysts.[19]
The synthesis of aromatic amines through the hydrogenation
of the corresponding nitroarenes is a basic chemical reaction.
Such reductions are also frequently applied in industry, as aro-
matic amines are important bulk chemicals, for instance, ani-
line, and intermediates for the production of fine chemicals,
pharmaceuticals, polymers, herbicides, and more.[1] A challenge
is the selective hydrogenation of the nitro groups in the pres-
ence of functional groups highly sensitive to hydrogenation
such as C=C bonds and nitrile and aldehyde substituents.[1]
Pioneering work involving the use of modified commercially
available noble-metal hydrogenation catalysts was reported by
Blaser and colleagues.[1,2] Recently, Pd-based noble-metal cata-
lysts were developed that can also function at atmospheric hy-
drogen pressure and at room temperature.[3] With regard to
nonclassic hydrogenation catalysts, Corma and Serna reported
a breakthrough in 2006.[4] They used Au nanoparticles support-
ed on TiO2 and observed a selectivity over 95% for the reduc-
tion of the nitro group in 3-nitrostyrene, 4-nitrobenzaldehyde,
4-nitrobenzonitrile, and 4-nitrobenzamide. The conservation of
the elemental resources of our planet is a global challenge,
and the replacement of noble metals by abundantly available
transition metals (base metals) is an appealing noble-metal
conservation strategy.[5] In this context, Beller and co-workers
introduced a cobalt catalyst[6] and a related iron catalyst[7] with
impressive selectivity and scope for the hydrogenation of ni-
troarenes.[8,9] Nickel is also an inexpensive base metal and is
Herein, we report novel mesostructured Ni@SiCN nanocom-
posite materials easy to synthesize and scale up. The meso-
structure is generated by an inexpensive polystyrene template,
spheres 60 nm in diameter, and well dispersed in organic sol-
vent, which is compatible with the generation of well-defined
Ni nanoparticles. The material was characterized by powder
X-ray diffraction (XRD), transmission electron microscopy
(TEM), scanning electron microscopy (SEM), IR spectroscopy,
and nitrogen physisorption. The nickel nanoparticles are cata-
lytically active in the hydrogenation of nitroarenes. For the first
time, we show that a reusable Ni catalyst is able to effect the
selective hydrogenation of nitroarenes in the presence of hy-
drogenation-sensitive functional groups such as C=C bonds
and nitrile, keto, aldehyde, and amide substituents.
Recently, Ewert et al.[17,18] showed that polystyrene could be
used as a soft template to generate a defined mesostructure in
SiCN materials. This strategy of structuring should be compati-
ble with the generation of metal–SiCN nanocomposites by
transmetalation, crosslinking, and pyrolysis, as recently report-
ed for a variety of metals.[13–15] To combine both synthesis pro-
cedures, first, polystyrene spheres with a diameter of 60 nm
(PS60) were dispersed in toluene (Figure 1). Next, we searched
for a suitable Ni complex for the introduction of the metal into
the mesostructured nanocomposite. The recently used nickel
precursors were not stable enough under the conditions suc-
cessfully applied for mesostructuring. A fine balance between
stability of the metal precursor to avoid reduction and metal
aggregation prior to pyrolysis should be ensured. On the other
hand, the nickel complex has to be reactive enough to accom-
plish transmetalation—metal transfer from the metal precursor
to the polysilazane. [(nacnac)2Ni][20] {nacnac=deprotonated
(E)-N-[(Z)-4-(phenylamino)pent-3-en-2-ylidene]aniline} was iden-
[a] G. Hahn, Dr. J.-K. Ewert, Dr. C. Denner, D. Tilgner, Prof. Dr. R. Kempe
Lehrstuhl Anorganische Chemie II
Universitꢀt Bayreuth
95440 Bayreuth (Germany)
E-mail: kempe@uni-bayreuth.de
Supporting Information for this article can be found under http://
dx.doi.org/10.1002/cctc.201600391.
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Figure 2. Characterization of the mesostructured Ni@PS60SiCN nanocompo-
site. Top) TEM images of Ni@PS60SiCN. Bottom left) Ni particle-size distribu-
tions calculated from the TEM images. Bottom right) Magnetic measure-
ments of Ni@PS60SiCN at 300 and 50 K indicating superparamagnetism of
the nanoparticles.
Magnetic measurements also provided evidence for the
presence of small Ni-NPs, as superparamagnetism was ob-
served (Figure 2, bottom right). PXRD was performed to con-
firm the presence of an amorphous SiCN matrix and metallic
Ni-NPs (Figure S1, bottom; see the Supporting Information).
The reflexes at Bragg’s angles of 2q=44.5 and 51.88 can be as-
signed to the (111) and (200) reflexes of a cubic Ni metal
phase. Peak broadening is in agreement with the particle size
observed by TEM. Also, TPR (temperature-programmed reduc-
tion) was performed by using unsupported NiO as a reference
and the Ni@PS60SiCN nanocomposite (Figure S5). An amount
equal to 6% of the total nickel amount is oxidized, and 94% is
metallic Ni. IR spectroscopy measurements confirmed a SiCN
matrix (Figure S2). The appearance of only one broad band at
n˜ =600–1300 cmÀ1 verified the presence of SiÀC and SiÀN
bonds. Scanning electron microscopy (SEM) (Figure 3, top) es-
Figure 1. Synthesis of the mesostructured Ni@PS60SiCN nanocomposite. First,
dispersion of the template polystyrene spheres with a diameter of 60 nm
(PS60) in toluene. Second, addition of commercially available polysilazane
HTT 1800, the nacnac–nickel complex, and DCP (dicumyl peroxide, as cross-
linker). Third, removal of the solvent and crosslinking at 1108C. Fourth, pyrol-
ysis with a tailored program at 9008C under a N2 atmosphere to form the
mesostructured Ni-SiCN nanocomposite.
tified as a suitable nickel precursor (Figure 1). After mixing a so-
lution of [(nacnac)2Ni] in toluene with the toluene dispersion of
PS60, the crosslinker and the polysilazane were added, and the
mixture was stirred for 1 h to fulfill the transmetalation
(Figure 1). Further crosslinking at 1108C without stirring and
slowly removing the solvent under vacuum enabled the de-
fined arrangement of the template and nickel in the cross-
linked polysilazane. During pyrolysis with the tailored program
at 9008C, the template was removed to obtain the mesopo-
rous structure and NiII was reduced to elemental nickel nano-
tablished
a homogenous distribution of mesopores in
Ni@PS60SiCN. Nitrogen sorption measurements (Figure 3,
bottom left) of Ni@PS60SiCN revealed a typical type IV isotherm
indicative of the presence of mesopores. The specific surface
area calculated by the Brunauer–Emmett–Teller (BET) method
was found to be 90 m2 gÀ1. In Figure 3 (bottom right), the cal-
culated pore-size distribution [N2 at À196.158C on carbon (slit
pore, NLDFT equilibrium model)] is shown. Ni@PS60SiCN exhib-
its >95% mesopores with a total pore volume of 0.283 mLgÀ1
and an average pore width of 8.2 nm.
particles under
(Figure 1).
a reductive atmosphere (H2 liberation)
A theoretical Ni/Si ratio of 1:20 was chosen for the synthesis
of Ni@PS60SiCN corresponding to 2.3 wt% of Ni. Inductively
coupled plasma optical emission spectrometry (ICP-OES)
measurements revealed 2.34 wt% nickel in the Ni@PS60SiCN
nanocomposite, which is a very good agreement between the
calculated and observed Ni contents. Ni@PS60SiCN was further
analyzed by TEM. TEM analysis indicated a homogenous distri-
bution of the nickel nanoparticles (Ni-NPs) in the mesostruc-
tured support of Ni@PS60SiCN (Figure 2, top). In addition,
a narrow Ni-NP distribution with the maxima at approximately
5.5 nm was observed (Figure 2, bottom left).
The selective hydrogenation of nitroarenes to the corre-
sponding anilines was evaluated in a 4:1 ethanol/water mix-
ture under 5.0 MPa hydrogen. Water was added to increase
the activity of the catalyst.[21] We compared the activity of the
Ni@PS60SiCN nickel nanocomposite introduced here to that of
a Ni@SiCN catalyst synthesized by using a slightly different
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Figure 4. Catalyst comparison. Top) Benchmark reaction; bottom left) com-
parison of catalyst loadings of both Ni catalysts for full conversion and
>99% selectivity [conditions: 1108C, 5.0 MPa H2, 1 mmol 1-bromo-3-nitro-
benzene in 5 mL ethanol/water (4:1), 20 h]; bottom right) recycling of the
Ni@PS60SiCN catalyst over five consecutive runs [conditions for 80% yield
(green): 1108C, 5.0 MPa H2, 0.5 mmol 1-bromo-4-nitrobenzene in 5 mL etha-
nol/water (4:1), 3 h, 6 mol% catalyst (1.76 mg Ni, 0.03 mmol, 75 mg nano-
composite); conditions for 40% yield (blue): 1108C, 5.0 MPa H2, 1.0 mmol 1-
bromo-3-nitrobenzene in 5 mL ethanol/water (4:1), 3 h, 4 mol% catalyst
(2.3 mg Ni, 0.04 mmol, 100 mg nanocomposite)], GC yield with n-dodecane
as internal standard. A conversion of 80% was chosen to clearly see catalyst
decomposition.
Figure 3. Pore characterization of the mesoporous Ni@PS60SiCN nanocompo-
site. Top) SEM images showing the mesostructuring of the nanocomposite.
Bottom left) Nitrogen sorption measurements. Bottom right) Calculated
pore-size distribution [calculation model: N2 at À196.158C on carbon (slit
pore, NLDFT equilibrium model)].
procedure recently disclosed by us.[14] Ni@SiCN was pyrolyzed
at 7008C. At this temperature, the support is more a highly
crosslinked polysilazane than a stable SiCN material. Owing to
low-temperature pyrolysis, remaining microporosity is ob-
served for such a material. Even at this lower pyrolysis temper-
ature of 7008C, NiII is reduced to metallic Ni under the reduc-
tive atmosphere during pyrolysis. These Ni-NPs were character-
ized by TEM (average particle size of 1.59 nm; Figure S3) and
PXRD (Figure S1). The pore characterization of the microporous
Ni@SiCN nanocomposite indicated 42% micropores, only very
small mesopores, a total pore volume of 0.062 mLgÀ1, and an
average pore width of 1.2 nm (Figure S4).
iodide, was observed. Only for the hydrogenation of the steri-
cally demanding ortho-substituted nitroarenes, the catalyst
loading was increased to ensure full conversion. In addition, re-
ducible functional groups were also successfully tolerated. For
example, nitrile, keto, aldehyde, amide, and even vinyl groups
were not hydrogenated by the catalyst (Table 1, entries 8–12).
The only byproduct formed in the reaction of 3-nitrostyrene
was 3-ethylaniline (Table 1, entry 12). Selective hydrogenation
was observed for heterocyclic nitroquinoline (Table 1, entry 16)
with conservation of the aromatic system. In addition, a sterical-
ly demanding aliphatic nitro compound was hydrogenated to
the corresponding amine (Table 1, entry 17). All of the above-
mentioned nitro substrates were hydrogenated by the
Ni@PS60SiCN catalyst with high selectivity (82–99%).
Both Ni catalysts showed catalytic activity and high selectivi-
ty in the hydrogenation of the nitro group at 1108C. In com-
parison to the microporous Ni@SiCN catalyst, the novel meso-
porous Ni@PS60SiCN catalyst was found to be more active in
the hydrogenation of 1-bromo-3-nitrobenzene to 3-bromoani-
line. It was possible to reduce the catalyst loading from 6 to
1 mol% under the same conditions (Figure 4, bottom left).
To evidence the robustness and recyclability of the meso-
structured catalyst, it was used in up to five runs (Figure 4,
bottom right). A conversion of 80% was chosen to clearly see
any catalyst decomposition. Between the runs, the catalyst was
washed with acetone to remove the substrate and then dried
and reused. Even after the fifth run, no decrease in the selec-
tivity or activity was observed. A leaching experiment demon-
strated that only 0.1% of the total amount of nickel leached
out of the nanocomposite during catalysis. Besides its unique
recyclability, the catalyst is distinguished by its high tolerance
to different functional groups. Various substituents on the
phenyl ring of the nitrobenzene were tolerated under the opti-
mized conditions (Table 1). Different halogenides, including
bromides, chlorides, and iodides, were tolerated (Table 1, en-
tries 1–7). No dehalogenation, not even in the presence of
In summary, we developed a novel mesoporous Ni-SiCN
nanocomposite catalyst. The mesostructuring with an inexpen-
sive polystyrene template was compatible with the generation
of metallic Ni nanoparticles with diameters of 5.5 nm. The
nickel nanoparticles, as the active sites of the catalyst, showed
high activity in the hydrogenation of nitroarenes to the corre-
sponding anilines. Additionally, the catalyst offered excellent
tolerance to reducible groups such as C=C bonds, heteroaro-
matics, and nitrile, keto, aldehyde, and amide groups. Another
specific advantage was the robustness of the catalyst, as it was
recycled and reused over multiple runs without a decrease in
activity or selectivity.
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Table 1. Hydrogenation of nitroarenes to the corresponding anilines with
the mesostructured Ni@PS60SiCN catalyst.[a]
Keywords: heterogeneous catalysis
mesoporous materials · nanocomposites · nickel
·
hydrogenation
·
Entry
1
Product
Conversion [%]
Selectivity [%]
[1] a) H.-U. Blaser, H. Steiner, M. Studer, ChemCatChem 2009, 1, 210–221;
b) H. K. Kadam, S. G. Tilve, RSC Adv. 2015, 5, 83391–83407; c) H.-U.
Blaser, Science 2006, 313, 312–313.
>99; isolated: 99
>99
2
>99
>99
>99
>99
[2] a) U. Siegrist, P. Baumeister, H.-U. Blaser in Catalysis of Organic Reactions
(Ed.: F. Herkes) Chemical Industries Series 75, Marcel Dekker Inc., New
York, 1998, pp. 207; b) R. Raja, V. B. Golovko, J. M. Thomas, A. Beren-
guer-Murcia, W. Zhou, S. Xie, B. F. G. Johnson, Chem. Commun. 2005,
2026–2028; c) H.-U. Blaser, U. Siegrist, H. Steiner, M. Studer in Aromatic
Nitro Compounds: Fine Chemicals through Heterogeneous Catalysis (Eds.:
R. A. Sheldon, H. van Bekkum), Wiley-VCH, Weinheim, 2001, pp. 389–
406.
[3] a) Z. Li, J. Li, J. Liu, Z. Zhao, C. Xia, F. Li, ChemCatChem 2014, 6, 1333–
1339; b) O. Verho, K. P. J. Gustafson, A. Nagendiran, C.-W. Tai, J.-E. Bꢁck-
vall, ChemCatChem 2014, 6, 3153–3159; c) O. Verho, A. Nagendiran, C.-
W. Tai, E. V. Johnston, J.-E. Bꢁckvall, ChemCatChem 2014, 6, 205–211.
[4] A. Corma, P. Serna, Science 2006, 313, 332–334.
3[b]
4
5
>99
>99
>99
>99
6[b]
>99
>99
>99
[5] R. M. Bullock, Science 2013, 342, 1054–1055.
[6] F. A. Westerhaus, R. V. Jagadeesh, G. Wienhçfer, M.-M. Pohl, J. Radnik,
A.-E. Surkus, J. Rabeah, K. Junge, H. Junge, M. Nielsen, A. Brꢂckner, M.
Beller, Nat. Chem. 2013, 5, 537–543.
7
84
[7] R. V. Jagadeesh, A.-E. Surkus, H. Junge, M.-M. Pohl, J. Radnik, J. Rabeah,
H. Huan, V. Schꢂnemann, A. Brꢂckner, M. Beller, Science 2013, 342,
1073–1076.
8
>99
>99
[8] For further examples of Co catalyst describing the hydrogenation of ni-
troarenes please see: a) Z. Zhao, H. Yang, Y. Li, X. Guo, Green Chem.
2014, 16, 1274–1281; b) Z. Wei, J. Wang, S. Mao, D. Su, H. Jin, Y. Wang,
F. Xu, H. Li, Y. Wang, ACS Catal. 2015, 5, 4783–4789; c) T. Stemmler, F. A.
Westerhaus, A.-E. Surkus, M.-M. Pohl, K. Junge, M. Beller, Green Chem.
2014, 16, 4535–4540.
[9] For further examples of Fe catalyst describing the hydrogenation of ni-
troarenes please see: a) O. Beswick, I. Yuranov, D. T. Alexander, L. Kiwi-
Minsker, Catal. Today 2015, 249, 45–51; b) R. Dey, N. Mukherjee, S.
Ahammed, B. C. Ranu, Chem. Commun. 2012, 48, 7982–7984; c) R. V. Ja-
gadeesh, K. Natte, H. Junge, M. Beller, ACS Catal. 2015, 5, 1526–1529.
[10] a) P. Baumeister, H. U. Blaser, W. Scherrer in Studies in Surface Science
and Catalysis, Elsevier, 1991; b) A. Corma, P. Serna, P. Concepciꢃn, J. J.
Calvino, J. Am. Chem. Soc. 2008, 130, 8748–8753; c) S. Pisiewicz, D. For-
menti, A.-E. Surkus, M.-M. Pohl, J. Radnik, K. Junge, C. Topf, S. Bach-
mann, M. Scalone, M. Beller, ChemCatChem 2016, 8, 129–134; d) P.
Serna, A. Corma, ACS Catal. 2015, 5, 7114–7121; e) W. Gerhar et al., U.S.
Patent 6,395,934, 2002.
[11] a) F. Cao, R. Liu, L. Zhou, S. Song, Y. Lei, W. Shi, F. Zhao, H. Zhang, J.
Mater. Chem. 2010, 20, 1078–1085; b) T. Fu, M. Wang, W. Cai, Y. Cui, F.
Gao, L. Peng, W. Chen, W. Ding, ACS Catal. 2014, 4, 2536–2543; c) P.
Zhang, C. Yu, X. Fan, X. Wang, Z. Ling, Z. Wang, J. Qiu, Phys. Chem.
Chem. Phys. 2015, 17, 145–150; d) T. Wang, Z. Dong, T. Fu, Y. Zhao, T.
Wang, Y. Wang, Y. Chen, B. Han, W. Ding, Chem. Commun. 2015, 51,
17712–17715; e) J. Xiong, J. Chen, J. Zhang, Catal. Commun. 2007, 8,
345–350; f) N. Mahata, A. F. Cunha, J. ꢄrf¼o, J. L. Figueiredo, Catal.
Commun. 2009, 10, 1203–1206; g) J. Wang, Z. Yuan, R. Nie, Z. Hou, X.
Zheng, Ind. Eng. Chem. Res. 2010, 49, 4664–4669; h) Y. Zheng, K. Ma, H.
Wang, X. Sun, J. Jiang, C. Wang, R. Li, J. Ma, Catal. Lett. 2008, 124, 268–
276; i) X. Liu, X. Ma, S. Liu, Y. Liu, C. Xia, RSC Adv. 2015, 5, 36423–36427.
[12] A heterobimetallic Rh/Ni nanocatalyst was previously shown to be ca-
pable of hydrogenating nitroarenes with reducible functional groups at
room temperature by using 0.1 MPa of H2: S. Cai, H. Duan, H. Rong, D.
Wang, L. Li, W. He, Y. Li, ACS Catal. 2013, 3, 608–612.
9
>99; isolated: 98
>99
>99
>99
10
11[b]
>99
>99
12
90
86
87
13[b]
>99
14[c]
15
>99; isolated: 93
>99
>99
isolated: 81
16
>99
>99
>99
17[b]
82
[a] Conditions: 1108C, 5.0 MPa H2, 1 mmol substrate, 20 h, 1 mol% cata-
lyst (0.7 mg Ni, 0.01 mmol, 30 mg). [b] Catalyst: 3 mol%. [c] Catalyst:
2 mol%.
[13] a) G. Glatz, T. Schmalz, T. Kraus, F. Haarmann, G. Motz, R. Kempe, Chem.
Eur. J. 2010, 16, 4231–4238; b) M. Zaheer, G. Motz, R. Kempe, J. Mater.
Chem. 2011, 21, 18825; c) D. Forberg, J. Obenauf, M. Friedrich, S.-M.
Hꢂhne, W. Mader, G. Motz, R. Kempe, Catal. Sci. Technol. 2014, 4, 4188–
4192.
Acknowledgements
[14] M. Zaheer, C. D. Keenan, J. Hermannsdçrfer, E. Roessler, G. Motz, J.
Senker, R. Kempe, Chem. Mater. 2012, 24, 3952–3963.
[15] M. Zaheer, T. Schmalz, G. Motz, R. Kempe, Chem. Soc. Rev. 2012, 41,
5102–5116.
We thank the Deutsche Forschungsgemeinschaft, SFB 840, project
B1, for financial support and Katja Dankhoff and Prof. Dr. Birgit
Weber for magnetic measurements.
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[16] a) S. K. T. Pillai, W. P. Kretschmer, M. Trebbin, S. Fçrster, R. Kempe, Chem.
Eur. J. 2012, 18, 13974–13978; b) S. K. T. Pillai, W. P. Kretschmer, C.
Denner, G. Motz, M. Hund, A. Fery, M. Trebbin, S. Fçrster, R. Kempe,
Small 2013, 9, 984–989.
[20] P. C. Healy, M. R. Bendall, D. M. Doddrell, B. W. Skelton, A. H. White, Aust.
J. Chem. 1979, 32, 727–735.
´
[21] M. Pietrowski, M. Zielinski, M. Wojciechowska, Catal. Lett. 2009, 128,
31–35.
[17] J. K. Ewert, C. Denner, M. Friedrich, G. Motz, R. Kempe, Nanomaterials
2015, 5, 425–435.
[18] J. K. Ewert, D. Weingarth, C. Denner, M. Friedrich, M. Zeiger, A. Schreiber,
N. Jꢁckel, V. Presser, R. Kempe, J. Mater. Chem. A 2015, 3, 18906–18912.
[19] For a related SiC catalyst please see: M. Zaheer, J. Hermannsdçrfer, W. P.
Kretschmer, G. Motz, R. Kempe, ChemCatChem 2014, 6, 91–95.
Received: April 4, 2016
Revised: May 4, 2016
Published online on && &&, 0000
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G. Hahn, J.-K. Ewert, C. Denner, D. Tilgner,
R. Kempe*
&& – &&
A Reusable Mesoporous Nickel
Nanocomposite Catalyst for the
Selective Hydrogenation of
Nitroarenes in the Presence of
Sensitive Functional Groups
Why so sensitive? A novel mesostruc-
tured Ni nanocomposite catalyst that is
easy to synthesize and scale up is intro-
duced. It is a reusable catalyst for the
selective hydrogenation of nitroarenes
to anilines. Highly hydrogenation-sensi-
tive groups such as olefins and alde-
hydes are tolerated.
&
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