Pd nanoparticles supported on a covalent triazine-based framework material: An efficient and highly chemoselective catalyst for the reduction of nitroarenes

Article abstract of DOI:10.1039/c8nj01404c

Pd nanoparticles anchored on a covalent triazine framework (Pd@CTF) were fabricated and employed to catalyze the transfer hydrogenation of nitro-compounds with formic acid as the hydrogen source. The results demonstrated that Pd@CTF displayed excellent catalytic activity and high chemoselectivity for the hydrogenation reaction at room temperature. Various substituted nitro-compounds were successfully converted to the corresponding amines in 0.2-2.5 h with other reducible functional moieties remaining intact. The high performance of Pd@CTF can be attributed to the synergistic interaction between the highly dispersed Pd nanoparticles and the covalent triazine framework support. The Pd@CTF catalyst can be readily reused for at least five consecutive runs without an obvious loss of its catalytic activity.

Full text of DOI:10.1039/c8nj01404c

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ISSN 1144-0546
PAPER
Jason B. Benedict et al.
The role of atropisomers on the photo-reactivity and fatigue of
diarylethene-based metal–organic frameworks
rsc.li/njc

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Pd nanoparticles supported on covalent triazine-based
framework material: An efficient and high chemosel-
ective catalyst for the reduction of nitroarenes
Received 00th January 20xx,
Accepted 00th January 20xx
Jie Li, Lihong Zhang, Xiaotong Liu, Ningzhao Shang*, Shutao Gao, Cheng Feng, Chun
Wang , Zhi Wang
DOI: 10.1039/x0xx00000x
∗
www.rsc.org/
College of Science, Hebei Agricultural University, Baoding 071001, China
Pd nanoparticles anchored on the covalentꢀtriazine framework (Pd@CTF) was fabricated and
employed to catalyze the transfer hydrogenation of nitroꢀcompound with formic acid as
hydrogen source. The results demonstrated that Pd@CTF displayed excellent catalytic activity
and high chemoselectivity for the hydrogenation reaction at room temperature. Various
substituted nitroꢀcompounds were successfully converted to the corresponding amines in 0.2ꢀ
2
.5 h with other reducible functional moieties remaining intact. The high performance of
Pd@CTF can be attributed to the synergistic interaction between the highly dispersed Pd
nanoparticles and the covalentꢀtriazine framework support. The Pd@CTF catalyst can be
readily reused for at least five consecutive runs without obvious loss of its catalytic activity.
3
issues resulting from H
2
handling . The other is the
1
. Introduction
extraction of hydrogen from other hydrogenꢀdonor
molecules, which is called transfer hydrogenation
reaction. Several hydrogen donors have been used as
Aromatic amines are important organic intermediates
and key precursors in synthetic organic chemistry as well
as in the chemical industry. They have been widely
utilized in various fields such as pharmaceutical, dye,
hydrogen source for catalytic transfer hydrogenation
4
(
CTH) of nitro chemicals, such as formic acid (FA) ,
5
6
1
sodium borohydride , hydrazine and ammonia borane
Among these available hydrogen sources, FA and its
fine chemicals and polymers . Therefore, much attention
7
.
has been paid to the development of efficient and
practical methods for the synthesis of aromatic amines.
The catalytic reduction of aromatic nitroarenes to the
corresponding aromatic amines is one of the most
extensive study methods . According to the hydrogen
sources, there are two types of the catalytic
hydrogenation of nitroꢀcompound. One is the use of
hydrogen (H ) as the hydrogen source of nitro
2
compounds for the catalytic hydrogenation reaction. But
this method is restricted because of the potential safety
salts have been extensively studied and applied in the
8
CTH of nitro compounds . Since FA is considered as a
2
safe, abundant and sustainable H storage material owing
2
to its high energy density with a gravimetric hydrogen
content of 4.4 wt%, excellent stability and nonꢀtoxicity.
Moreover, FA can be produced in large quantities by the
hydrogenation of CO
photosynthesis .
2
, biomass processing and artificial
9
In recent years, several noble metal catalysts have
been developed for the CTH of nitroꢀcompound with FA
10
as the hydrogen donor . For instance, Ag48Pd52/WO2.72
catalyst fabricated by Sun et al was used to catalyze the
College of Sciences, Hebei Agricultural University, Baoding 071001, P. R. China.
Tel.: +86 312 7528291. Eꢀmail: chunwang69@126.com
ningzhao611@126.com N. Shang
（C. Wang）,
o
hydrogenation of nitroarenes at 120 C in the presence of
（
）
8
†
Electronic Supplementary Information (ESI) available: Chemicals and FA . Cao et al reported an Au/rutile catalyst for the CTH
characterization apparatus, TEM image and particle size of Pd@CTF and recycled
Pd@CTF, the durability test and filtration test, the kinetic curves of the
of nitroarenes with toluene as the reaction solvent at
o
10
hydrogenation of nitrobenzene at different reaction temperatures, effect of 60 C employing FA as the hydrogen donor . Ebitani et
solvent, comparison with reported catalysts tested for reduction of nitroarenes to
anilines. See DOI: 10.1039/x0xx00000x
al prepared a Pd/ZrP catalyst to catalyze the transfer
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hydrogenation of the nitroarenes using FA as the 2.1 Synthesis of Pd@CTF
Journal Name
o
11
hydrogen resource at 40 C in ethanol media . Though
great progress has been achieved in the CTH of nitroꢀ
compound these years, the reported methods still have
The catalyst preparation process was illustrated in Scheme
. The CTF was prepared by oneꢀpot solvothermal reaction
according to the reported method with some modifications
In a typical process, melamine (5.2 mol, 6.55 g) and Et
15.0 g) were dissolved in 500 mL DMF, The mixture was
1
28
.
10
some drawbacks such as using toxic solvents , high
3
N
8
12
catalyst dosage and harsh reaction conditions
.
(
Twoꢀdimensional (2D) covalent organic frameworks
COFs) are burgeoning nanoporous materials synthesized
ultrasonicated for 10 min. Then the cyanuric chloride (5.0
mol, 9.20 g) was added into the mixture and sonicated for 30
min. Subsequently, the mixture was transformed into a 100
mL Teflonꢀlined stainless steel autoclave and heated in an
(
by assembling 1organic building blocks via strong
3
covalent bonds . The wellꢀdefined crystalline porous
structures together with designed functionalities offer the
COF materials distinctive application potential in
o
oven at 120 C for 24 h under autogenous pressure. After
cooling naturally to room temperature, the milk white solid
was separated by centrifugation and rinsed with ethanol and
deionized water for five times. The white solid (named as
1
4
different fields, such as optoelectricity , adsorption gas
8
, 15, 16
17, 18
storage
and catalysis
. Covalent triazineꢀbased
frameworks (CTFs) are a new class of COFs first
synthesized by Thomas and coꢀworkers via ionothermal
trimerization of aromatic nitriles. CTFs exhibit high
nitrogen content, highly ordered structures, large πꢀ
o
CTF) was dried at 80 C in vacuum oven for 4 h.
For the fabrication of Pd@CTF, 90 mg of CTF and 8.35
ꢀ1
mL H
2
PdCl
4
solution (2 mg mL ) were added into a 25 mL
round bottomed flask and ultrasonicated for 10 min. Then the
solution was stirred for at room temperature.
Subsequently, 1.3 mL NaBH
added dropwise and stirred for 2 h. The product was collected
by centrifugation, washed with H O until the pH reached 7,
19
electron systems, rich porosities , as well as high
4
h
20, 21
chemical and thermal stability
, which deliver them a
ꢀ1
4
(1.0 mol L ) solution was
promising candidate for energy gas storage and catalyst
support materials. To date, researches on the properties
and applications of CTFs demonstrated that CTFs
showed outstanding performance in catalysis and gas
2
o
and dried at 60 C in vacuum oven for 4 h to yield the
Pd@CTF.
2
1ꢀ24
storage
trifluoromethanesulfonic
trimerization reactions was successfully used2 as
. For example, the CTF synthesized by the
acidꢀcatalyzed
nitrile 2.2 Catalytic reduction of nitroarenes
The transfer hydrogenation of nitroarenes reactions
were carried out at room temperature. Firstly, 5 mg of the
prepared catalyst, 1.0 mmol nitrobenzene, 5 mmol formic
acid and 5 mmol ammonium formate were added into 5
mL of the mixture solution of ethanolꢀwater (4:1, v/v).
2, 23
photocatalyst support for carbon dioxide capture
.
With 4,4’ꢀdicyanobiphenyl as building block, CTF
containing pyridinic nitrogen has been prepared and
applied as an effective electrocatalysts for oxygen
2
4, 25
reduction reaction
. A mixedꢀnitrile linker strategy
o
Then the mixture was stirred at 25 C for a certain time.
was introduced for the preparation of CTFs materials
The reaction progress was monitored by thin layered
chromatography (TLC) and gas chromatography (GC).
The conversion and selectivity were calculated from the
GC data. After completion of the reaction, the product
was extracted with ethyl acetate (3×5 mL) and dried over
anhydrous MgSO . The identification of the products was
4
confirmed by GC. The recovered catalyst was separated
by centrifugation and washed with water and methanol to
2
6,
with higher CO
.
2
uptake and higher CO
2 2
/N selectivity
2
7
However, the application of CTFꢀbased catalyst in the
CTH of nitroꢀcompound with FA as the hydrogen donor
still remains unexplored.
In this work, a CTF was prepared by one pot
solvothermal reaction of cyanuric chloride and
melamine, and then Pd nanoparticles (NPs) were
immobilized on the CTF by an impregnation method
o
remove the inorganic and organic part, then dried at 80 C
overnight in vacuum for another consecutive reaction
followed by reduction with NaBH
4
. Due to the
coordination effect of nitrogenꢀcontaining groups in the
run
.
22
CTF and the nanoscale confinement effect of CTFs , Pd
NPs were well dispersed on the CTF. To investigate the
catalytic performance, the Pd@CTF was used for the first
time to catalyze the transfer hydrogenation of nitro
compounds using FA and ammonium formate (AF) as
hydrogen source. As expected, the Pd@CTF exhibited
outstanding catalytic activity and selectivity for the CTH
of nitroꢀcompound at room temperature.
3
. Results and Discussion
3.1 Characterization of the catalyst
The size and morphologies of Pd@CTF were
characterized by transmission electron microscopy
TEM). As shown in the images of TEM (See Fig. 1A,
(
S1A), Pd NPs are uniformly distributed on the CTF,
which can be ascribed to the coordination effect of
nitrogenꢀcontaining groups in the CTF and the
confinement effect of the CTF. The crystal plane spacing
of Pd was measured as 0.221 nm (Fig. 1B), which is
2
. Experimental section
The relevant reagents and instruments are given in the
Electronic Supporting Information (ESI).
2
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29
consistent with the result reported in the reference . The size of Pd particles was 4.25 ± 0.43 nm on the basis of a
size distribution of Pd nanoparticles was investigated count of more than 100 individual nanoparticles via TEM
using highꢀresolution TEM. As shown in the particle size analysis. The content of palladium in the Pd@CTF was
distribution diagram of Pd@CTF (Fig. S2A), the mean 10 wt%, which was determined by ICPꢀAES.
Scheme 1. Schematic illustrate of the preparation process of the Pd@CTF catalyst and the catalytic hydrogenation of nitroarenes
Fig. 1 TEM images of Pd@CTF.
Fig. 3 the N adsorptionꢀdesorption isotherms of Pd@CTF and
2
CTF.
Fig. 2 XRD images of CTF, Pd@CTF and reused Pd@CTF
.
The Xꢀray diffraction (XRD) patterns of the samples
was shown in the image (Fig. 2). The materials displayed
o
three diffraction peaks at 2
θ
= 10.5°, 20.3 , and 27.5°,
which were represented to the (001) (200) and (100)
Fig 4. The XPS images of all elements of Pd@CTF (A),
the spectrum of N 1s (B), C 1s (C) and Pd 3d (D) of
Pd@CTF.
30
planes of CTF, respectively . The minor reflection peak
°
at 2θ = 27.5 was attributed to the (100) face of CTF
typical interlayer stacking reflection of conjugatedo
aromatic systems. The broad peak of Pd@CTF at 40.1
Xꢀray photoelectron spectroscopy analysis was
(
111) can be attributed to the high dispersion of Pd NPs conducted to further illustrate the chemical composition
on the CTF. The porosity and surface areas of the CTF of the Pd@CTF (Fig. 4). The C 1s peaks of CTF emerges
and Pd@CTF were measured by nitrogen adsorptionꢀ two main peaks (Fig. 4C), which can be corresponding to
2
2
desorption analysis at 77 K, and the surface area was sp CꢀC bonds in triazine ring (284.8 eV) and sp ꢀbonded
5
2
ꢀ1
2 ꢀ1
5.0 m g (Fig. 3) for CTF and 39 m g for the carbon in aromatic rings. The N 1s peak at 399.1 eV can
Pd@CTF. The lower surface area of Pd@CTF can be be ascribed to pyridinicꢀlike in the triazine unit (CꢀN=C)
ascribed to the fact that the Pd nanoparticles loaded in the (Fig. 4B)
31, 32
. The Pd spectrum shows peaks of Pd 3d5/2
pores of the CTF.
and Pd 3d3/2 at 335.3 eV and 340.5 eV (Fig. 4D),
respectively, which are ascribed to the metallic palladium
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0
ꢀ1 ꢀ1
(
Pd ). Two other peaks of Pd 3d5/2 peak and Pd 3d3/2 peak TOF was 5 mol Pd mol
h
and only 60% conversion of
at 337.5 eV and 342.4 eV are related to palladium oxide nitrobenzene was achieved after 12 h under the similar
2
+ 33
(
Pd ) . The presence of oxidized Pd species maybe due reaction conditions (Table 1, entry 3). The results
to the oxidation of metallic Pd left in an oxygenꢀ0 demonstrated that the CTF support plays a key role for
containing environment. According to the XPS data, Pd the high catalytic activity of the Pd@CTF. The mean size
were formed as the major phase in the catalyst.
of Pd particles in Pd@CTF (4.25 nm) is smaller than that
in Pd/C (5.5 nm, Fig. S3), which can be ascribed to that
both the coordination effect of abundant nitrogen in the
CTF and the confinement effect of the CTF facilitates the
3.2 The catalytic hydrogenation of nitroarenes
To evaluate the catalytic performance of different
34
dispersion of Pd nanoparticles . Based on the above
results, it is safe to say that the high catalytic
performance of Pd@CTF can be ascribed to the
synergistic effect of the highly dispersed Pd
nanoparticles and the covalentꢀtriazine framework.
catalysts, the reduction of nitrobenzene was selected as a
benchmark system. No conversion of nitrobenzene was
observed after 6 h in absence of catalyst (Table 1, entry
1
) or in the case of CTF (Table 1, entry 2). To our
delight, Pd@CTF exhibited high catalytic activity and
electivity (>99%) for the catalytic transfer hydrogenation
of nitrobenzene. The results revealed that Pd
nanoparticles were the catalytic active sites for the
hydrogenation reaction. The reaction catalyzed by
The effect of the type of solvent was also investigated
(
2
Table S1). When H O and ethanolꢀwater (v/v = 1:4, 2:3)
were employed as the reaction solvent, the desired
product was obtained after 0.3 h, but the selectivity was
poor (Table S1, entries 4ꢀ6). To our delight, the reaction
performed efficiently in 0.2 h with 99% selectivity and
conversion with ethanol or ethanolꢀwater (4:1, v/v) as the
solvent (Table S1, entries 1ꢀ2). Hence, we chose ethanolꢀ
water (v/v = 4:1) as the solvent.
o
Pd@CTF can be completed after 0.2 h at 25 C with 5.0
equiv formic acid and 5.0 equiv ammonium formate as
the hydrogen source, getting the biggest turnover
ꢀ
1
ꢀ1
frequency (TOF) of 495 mol Pd mol
h (Table 1, entry
4
). However, for commercial available Pd/C catalyst, the
Table 1. Optimization of the reaction conditions for the transfer hydrogenation of nitrobenzene with different
[a]
conditions over Pd@CTF catalyst
Dosage
mol% Pd)
ꢀ1
Entry Catalysts
FA (mmol) Formate (mmol) Time (h) Con. (%) Sel. (%) TOF (h )
(
1
2
3
4
5
6
7
8
9
ꢀ
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
0.1
0.25
0.5
5
5
5
5
5
5
6
6
ꢀ
ꢀ
ꢀ
CTF
ꢀ
ꢀ
ꢀ
Pd/C
5
12
0.2
0.3
1.5
12
1
60
>99
>99
85
5
Pd@CTF
Pd@CTF
Pd@CTF
Pd@CTF
Pd@CTF
Pd@CTF
Pd@CTF
Pd@CTF
Pd@CTF
Pd@CTF
Pd@CTF
5
>99
>99
>99
90
495
283
66
[
b]
5
5
5
0
5
>99
>99
>99
>99
>99
97
0
7.5
99
[
c]
5
5
>99
>99
>99
85
[
d]
5
5
2
49.5
8.25
7.1
45
1
0
1
2
3
4
2.5
1
2.5
1
12
12
22
4
1
1
1
1
5
5
>99
>99
>99
>99
>99
>99
5
5
24.8
132
5
5
1.5
o
[
a] Reaction conditions: 1 mmol nitrobenzene, catalyst, FA, NH
4
COOH, EtOH:H
2
O (v/v, 5 mL), 25 C, GC analysis
using ꢀdecane as an internal standard. [b] H O 5 mL, [c] HCOOK, [d] HCOONa.
n
2
Furthermore, we filter and validate the effect of the 90% yield after 12 h, respectively. When
type and dosage of hydrogen sources on the CTH of HCOOH/HCOOK (1:1, molar ratio) (Table 1, entry 8) or
nitrobenzene (Table 1 entries 6ꢀ9). When only 5.0 equiv HCOOH/HCOONa (1:1) (Table 1, entry 9) were used,
formic acid (Table 1, entry 6) or 5.0 equiv ammonium relative long reaction time (1 h and 2 h, respectively),
formate (Table 1, entry 7) was used as the hydrogen were required to complete the reaction. When the dosage
source, aniline was gained in 99% yield after 1.5 h and of hydrogen donor decreased from 5 equiv to 2.5 equiv
4
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and 1.0 equiv, the yields of aniline were 99% and 85% after 12 h reaction, respectively (Table 1, entries 10, 11).
[
a]
Table 2 Reduction of nitro compounds to corresponding amines
ꢀ
1
Entry
Substrate
Product
Time(h)
Con.(%)
Sel.(%)
TOF(h )
1
2
0.2
1.2
>99
95
>99
>99
495
79.2
3
4
5
NO
2
0.75
0.6
>99
>99
>99
>99
>99
>99
132
165
198
0.5
6
7
8
9
0.6
0.33
2
90
>99
92
>99
>99
>99
95
150
300
46
H
2
N
NO
2
2
>99
>99
49.5
198
1
0
1
0.5
>99
1
1.5
0.6
2.5
>99
>99
91
>99
>99
>99
66
12
165
36.4
[
b]
1
3
[
[
b]
b]
1
4
5
2
2
>99
>99
>99
>99
49.5
49.5
1
o
[
a] substrate 1.0 mmol, Pd@CTF (1.0% mol), EtOH/H O (v/v = 4:1) (5 mL), FA (5 mmol), NH COOH (5 mmol), 25 C, GC analysis
2
4
o
using nꢀdecane as an internal standard; [b] 50 C.
We also investigated the influence of the dosage of Pd even after 50 min of reaction under identical conditions
on the catalytic performance. When the dosages of (Fig. S4B), which demonstrated that the filtrate did not
Pd@CTF catalyst were 0.1, 0.25, 0.5 and 1.0 mol% Pd, contain active Pd species. In addition, ICPꢀAES analysis
the reaction time needed 22, 4.0, 1.5 and 0.2 h, indicated that no metal can be detected in the liquid
respectively, to complete the reaction (Table 1, entries solution. The results indicated that the Pd@CTF is a
1
2ꢀ14, 4).
heterogenous catalyst.
To confirm that the reduction reaction of nitrobenzene
As our main concerns were the stability and durability
catalyzed by Pd@CTF is a heterogeneous process, a of the catalyst, we investigated the activity of the
filtration test was performed by separating Pd@CTF recycled Pd@CTF catalyst under the optimum reaction
catalyst after 10 min. No further conversion to the conditions. The results indicated that the yield of 91% of
product in the remaining liquid solution was observed the product was well retained after five consecutive runs
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(
Fig. S4A). Form the TEM image of the recycled to 99% were obtained. But longer reaction time was
Pd@CTF (Fig. S1B), we can see that the Pd needed for ꢀsubstituted nitroarenes due to the steric
nanoparticles loaded on CTF remained good dispersion hindrance (Table 2, entries 2ꢀ3). Generally, several other
and no obvious particles agglomeration can be observed. groups, such as ꢀhydroxyl, ꢀhydroxyl,
The mean size of Pd nanoparticles after five cycles was hydroxymethyl, ꢀamino and ꢀmethylol triumphantly,
.34 ± 0.5 nm Fig. S2B). In addition, XRD results were transformed to corresponding amines compounds
o
p
o
pꢀ
p
p
5
(
o
indicated that no obvious diffraction peak change can be with high selectivity at 25 C (Table 2, entries 4ꢀ7).
observed between fresh and recycled catalyst (Fig. 2), Particularly, the nitro compounds functionalized with the
which indicated good dispersion of metal and high challenging reducible functional moieties, such as
durability of Pd@CTF. The peaks of the reused catalyst ketone, aldehyde group and nitroꢀgroup, were successful
is slightly higher than that of the fresh catlyst, which can conversed to the corresponding amines (Table 2, entries
be assigned to the better crystallinity of the reused 8ꢀ12). But for 1ꢀnitronaphthalene, 4ꢀnitrile substituted
catalyst. In addition, the surface area of the reused nitrobenzene, and aliphatic nitro compounds, the reaction
o
catalyst has not obvious change with that of the fresh temperature of 50 C was required to achieve full
catalyst (Fig. 3). The above results demonstrated that conversion in 1.5ꢀ2.5 h (Table 2, entries 13ꢀ15).
Pd@CTF was a robust, recyclable and efficient catalyst Compared with the reported heterogeneous catalysts,
in the catalytic reduction of nitro compounds.
Pd@CTF exhibited high catalytic activity for the CTH of
To gain the activation energy ( a) of the transfer nitroarenes, the value of TOF surpassed most of the
E
hydrogenation reaction catalyzed by Pd@CTF, we reported catalysts (Table S2). The results indicated that
studied the transfer hydrogenation of nitrobenzene at the covalentꢀtriazine framework is a promising platform
o
o
o
0
C, 15 C and 25 C, respectively. The apparent rate for exploring efficient metal nanocatalysts.
constant ( ) for the pseudo firstꢀorder reaction can be
k
defined as in Eq. 1:
4
. Conclusions
Ct
ln
= ꢀk t
(1)
In summary, Pd nanoparticles supported on CTF was
C0
successfully prepared and employed as an efficient
catalyst for the CTH of various nitroarenes at room
temperature with FA/NH COOH as the hydrogen donor.
4
The synergistic effect of the highly dispersed Pd NPs and
the covalentꢀtriazine framework led to the outstanding
catalytic performance of the catalyst. The approach in
this work can be potentially used to develop novel
efficient catalysts for chemoselective hydrogenations in
the future.
Ea
−
RT
k
=
Ae
(2)
Ea 1
ln k =
+ ln A (3)
(
−
)
R
T
0
C : the initial concentration of nitrobenzene;
C
k
t
: the concentration of nitrobenzene at a certain time;
: the rate constant;
t
E
: the reaction time;
a: apparent activation energy of the reaction.
Conflicts of interest
There are no conflicts to declare.
It can be seen that the rate constant increases with
k
increasing the reaction temperature, the result proved that
the reaction rate and the yield of nitrobenzene evidently
relies on the temperature (Fig S5). According to the
Acknowledgements
Financial supports from the National Natural Science
Foundation of China (21603054), the Natural Science
Foundation of Hebei Province (B2015204003, B2016204131,
B2018204145), the Young Topꢀnotch Talents Foundation of
Hebei Provincial Universities (BJ2016027), the Natural
Science Foundation of Hebei Agricultural University
Arrhenius plot equation (Eq. 2,3): the apparent
Ea of the
ꢀ1
catalytic hydrogenation of Pd@CTF was 28 kJ·mol ,
which revealed that the combination of Pd and the CTF
obviously reduced the apparent activation energy. It
shows that the reaction can be carried out at a lower
35ꢀ37
temperature and save energy.
(
ZD201613, LG201709, LG201711), are gratefully
Based on the optimum conditions, we then tested the
catalytic activity of the Pd@CTF for the CTH of various
acknowledged.
1
substituted nitroarenes (Table 2). The HꢀNMR data of
the products were provided (See ESI). The desired
corresponding amines were obtained in excellent yields
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DOI: 10.1039/C8NJ01404C
Pd nanoparticles supported on covalent triazine-based framework
material: An efficient and high chemosel-ective catalyst for the
reduction of nitroarenes
Jie Li, Lihong Zhang, Xiaotong Liu, Ningzhao Shang*, Shutao Gao, Cheng Feng,
∗
Chun Wang , Zhi Wang
College of Science, Hebei Agricultural University, Baoding 071001, China
Well-dispersed Pd nanoparticles supported on triazine-based framework was
prepared and the material displayed excellent catalytic activity for the transfer
hydrogenation of nitroarenes. The reactions can be conducted smoothly at room
temperature with formic acid and ammonium formate as hydrogen source.