A graphdiyne-based carbon material for electroless deposition and stabilization of sub-nanometric Pd catalysts with extremely high catalytic activity

Article abstract of DOI:10.1039/c9ta03621k

The development of sub-nanometric metal particles (<1 nm) as advanced heterogeneous catalysts has received considerable interest due to their outstanding catalytic performance, while the synthesis and stabilization of sub-nanometric catalysts (SNCs) without using additional surface capping agents remains a challenge. Herein, we report the synthesis of novel three-dimensional pyrenyl graphdiyne (Pyr-GDY) ultrafine nanofibers (3-10 nm), which can serve as an ideal substrate for electroless deposition and stabilization of Pd SNCs through the terminal uncoupled acetenyl groups in Pyr-GDY, with an average Pd particle size of only 0.83 nm. The as-synthesized Pd/Pyr-GDY composite shows extremely high catalytic activities for the reduction of nitroarenes to arylamines and Suzuki coupling reactions, 300 and 25 times higher than those of commercial Pd/C, respectively. The outstanding catalytic performance can be ascribed to the sub-nanometric Pd particles with a "clean surface", and the unique three-dimensional network structure of Pyr-GDY, being favorable for rapid mass transfer. Our result provides an ideal carbon material for electroless deposition and stabilization of other SNCs with a "clean surface", which will display outstanding catalytic activity for various catalytic reactions.

Full text of DOI:10.1039/c9ta03621k

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ISSN 2050-7488
PAPER
Kun Chang, Zhaorong Chang et al.
Bubble-template-assisted synthesis of hollow fullerene-like
MoS nanocages as a lithium ion battery anode material
2
rsc.li/materials-a

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DOI: 10.1039/C9TA03621K
Journal Name
ARTICLE
A Graphdiyne-Based Carbon Material for
Electroless Deposition and Stabilization
of Sub-Nanometric Pd Catalysts with
Extremely High Catalytic Activity
Received 00th January 20xx,
Accepted 00th January 20xx
DOI: 10.1039/x0xx00000x
a
a
a
a
Liang-Liang Yang, Hong-Juan Wang, Juan Wang, Yu Li,
www.rsc.org/
,a
,a,b
Wen Zhang* and Tong-Bu Lu *
The development of sub-nanometric metal particles (<1 nm) as advanced
heterogeneous catalysts has received considerable interest due to their
outstanding catalytic performance, while the synthesis and stabilization of
sub-nanometric catalysts (SNCs) without using additional surface capping
agents remains challenge. Herein, we report the synthesis of a novel three-
dimensional pyrenyl graphdiyne (Pyr-GDY) ultrafine nanofibers (3~10 nm),
which can serve as an ideal substrate for electroless deposition and
stabilization of Pd SNCs through the terminal uncoupled acetenyl groups in
Pyr-GDY, with an average Pd particle size of only 0.83 nm. The as-
synthesized Pd/Pyr-GDY composite shows extremely high catalytic activities
for the reduction of nitroarenes to arylamines and Suzuki coupling reactions,
3
00 and 25 times higher than those of commercial Pd/C, respectively. The
outstanding catalytic performance can be ascribed to the sub-nanometric Pd
particles with “clean surface”, as well as the unique three-dimensional
network structure of Pyr-GDY, being favorable for rapid mass transferring.
Our result provides an ideal carbon material for electroless deposition and
stabilization of other SNCs with “clean surface”, which will display
outstanding catalytic activity for various catalytic reactions.
Introduction
The catalytic performance of heterogeneous nanocatalysts
is seriously dependent on their sizes of nanoparticles, the
smaller nanoparticles with larger accessible surface area
1
usually display higher catalytic activity. Recently, sub-
nanometric catalysts (SNCs) with the sizes of nanoparticles less
than 1 nm have drawn particular attention, as they show
outstanding catalytic performance compared with traditional
2
-5
nanocatalysts. However, with the decrease in particle size,
the surface energy increases, which usually results in serious
aInstitute for New Energy Materials and Low Carbon Technologies, School of
Material Science & Engineering, Tianjin University of Technology, Tianjin 300384,
6-7
nanoparticle aggregation. To overcome this problem, various
8
-9
10-11
People’s Republic of China. *Email: zhangwen@email.tjut.edu.cn, surface capping agents, including surfactants, polymers,
lutongbu@mail.sysu.edu.cn.
12-13
5
14-15
dendrimers,
organic cages, and other organic ligands
b
MOE Key Laboratory of Bioinorganic and Synthetic Chemistry, School of
have been used to reduce the surface energy and stabilize the
SNCs. Unfortunately, the surface capping agents will block the
active sites and subsequently decrease the catalytic activity of
SNCs. In addition, noncovalent interactions between the
Chemistry, Sun Yat-Sen University, Guangzhou 510275 (China).
Liang-Liang Yang and Hong-Juan Wang contributed equally to this work.
Electronic Supplementary Information (ESI) available: [details of any
supplementary information available should be included here]. See DOI:
0.1039/x0xx00000x
†
1
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Journal Name
capping agents and reactants will also affect the catalytic activities 300 and 25 times higher than those of commercial
View Article Online
16
DOI: 10.1039/C9TA03621K
activity of SNCs. Therefore, SNCs with “clean surface” Pd/C for the reduction of nitroarenes to arylamines and Suzuki
without capping agents) are more desirable and coupling reaction, respectively.
(
straightforward to understand the structure-activity
relationship of these SNCs, which is regarded as the heart and
most challenging tasks in heterogeneous catalytic
investigations. In this context, developing suitable
nanomaterials as supports for the nucleation and growth of
stable SNCs with “clean surface” is most desired.
1
7
Previous studies have shown that graphene oxide (GO)
and copper foil supported carbon nanotube
18-20
can be used as
the carbon-supports for the electroless deposition of noble
metals nanoparticles, without the aid of extra surface capping
agents or reducing agents, in which the reduction of noble
metals ions occurs through a galvanic-reaction process by the
electron transfer through GO and carbon nanotube,
accompanying with the oxidation of GO and copper foil.
III
II
Carbon nanotube can also in-situ reduce Au and Pt salts to
generate Au and Pt nanoparticles.
20
Such electroless
deposition method provides an opportunity for the
preparation of SNCs with “clean surface”. Unfortunately, so far
the smallest particle size of the deposited nobel metal
nanoparticles has been reported to be 3.5 nm,17 SNCs
Scheme 1. Preparation of Pd/Pyr-GDY composite and its catalytic reactions.
deposited on carbon-supports has not been achieved yet.
Recently, a new family of booming carbon materials of
2
Results and discussion
Synthesis and characterization of Pyr-GDY. The synthetic route of
Pyr-GDY is shown in Scheme S1. Firstly, 1,3,6,8-
tetra[(trimethylsilyl)ethynyl]pyrene (TEP-TMS) was synthesized
graphdiyne (GDY), which contain both sp- and sp -carbon
atoms, have drawn much attentions.2
1-28
Owing to the
existence of electron-rich acetylene bonds, GDY can bind with
nobel metal Pt to form stable single-atom Pt catalyst for
2
3
efficient electrocatalytic hydrogen evolution. GDY can even
stabilize the zero valence single nickel and iron atoms by
electrochemical deposition metal ions within its matrices.22 As
the reduction potential of GDY is relatively low (-0.33 V vs
33
according to the literature method, its purity was confirmed
by NMR and high-resolution mass spectroscopy (HRMS,
Figures S1-S3). As metallic copper can release CuI/II ions in
34-35
+
2+
alkaline solutions,
and both Cu and Cu are able to act as
SHE),2 GDY can also directly reduce Pd metal ions to in-situ
generate Pd nanoparticles with a size of 4 ± 0.5 nm.29 To
decrease the reduction ability of GDY for getting smaller Pd
nanoparticles, GDY was oxidized to graphdiyne oxide (GDYO)
9
II
36-37
the catalysts for Glaser coupling reaction,
we choose
copper foil as both supporting substrate and catalyst for
terminal alkyne coupling reaction of TEP monomer. As shown
in Scheme 1, after desilication of TEP-TMS, the TEP monomer
was slowly added into a three-neck flask containing pyridine
and copper foils. In this process, the four terminal alkynyls of
TEP were coupled with each other to form extended π-
conjugated carbon skeleton containing diacetylene links and
pyrenyl groups. As a result, a dark brown film was formed on
the surface of copper foil (Figure S4).
29
to generate a reduction potential of -0.21 V, and GDYO was
used as a support for electroless deposition Pd nanoparticles
to get a smaller size of 1.3 ± 0.1 nm.29 However, the synthesis
of GDYO needs to use strong oxidants such as concentrated
H
2
SO
4 3 4
/HNO mixture and KMnO , which will damage the
30-32
acetylene bonds of graphdiyne inevitably.
Therefore,
developing new GDY-based materials for electroless
deposition SNCs remains great challenge.
Herein, we reported the synthesis of a novel GDY material
through a modified Glaser−Hay coupling reaction of 1,3,6,8-
tetraethynylpyrene (TEP) monomer. As shown in Scheme 1,
pyrenyl graphdiyne (Pyr-GDY) ultrafine nanofibers, with
diameters of 3~10 nm, can be formed on the surface of copper
foil. This unique three-dimensional (3D) cross-linked network
can serve as an ideal substrate for electroless deposition of Pd
SNCs to form Pd/Pyr-GDY composite, with an average size of
only 0.83 nm. Benefiting from the sub-nanometric structure of
Pd nanoparticles, as well as the 3D cross-linked network of Pyr-
GDY, Pd/Pyr-GDY shows extremely high catalytic activities
towards various liquid-phase catalytic reactions, with the
2
| J. Name., 2012, 00, 1-3
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−
1
1
236.4, 1364.5, 1489.2, 1608.5, 1973.7 and 2176.1 cm ,
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−
1
DOI: 10.1039/C9TA03621K
respectively. The peak at 1236.4 cm corresponds to the C-H
in-plane bending vibration. The peaks at 1364.5, 1489.2 and
1
1
608.5 cm− are ascribed to the C-C stretching vibration of
3
8-39
-1
pyrene ring.
The peaks at 1973.7 and 2176.1 cm can be
assigned to the vibrations of terminal uncoupled alkynyl and
21,40-42
conjugated diacetylene links, respectively.
XPS
measurements indicate that Pry-GDY is mainly composed of
carbon element (Figure S6). The signal of oxygen might
originate from the absorption of oxygen from the air, and/or
from partial oxidation of alkynyl group. In detail, the C1s peak
of Pyr-GDY can be deconvoluted into four sub-peaks at 284.6,
2
85.3, 286.9 and 288.5 eV, respectively, corresponding to C=C
2
1
43-44
(sp ), C≡C(sp ), C−O, and C=O bonds, respectively.
The area
2
ratio of sp and sp hybridized carbons is close to 0.5 (Table S1),
which is consistent with the proposed structure of Pyr-GDY.
Electroless deposition of Pd SNCs on Pyr-GDY nanofibers.
As Pyr-GDY contains abundant sp hybridized carbons,
especially numerous terminal uncoupled acetenyl groups, it
may serve as a good substrate for electroless deposition of
metal species. Firstly, the redox property of Pyr-GDY was
evaluated by ultraviolet photoelectron spectra (UPS).
20,45-46
According to the equation in Figure S7,
the reduction
potential of Pyr-GDY was calculated to be + 0.23 V vs SHE,
20
which is lower than carbon nanotube (+ 0.5 V vs SHE) and
1
7
graphene oxide (+ 0.27 V vs SHE), indicating Pyr-GDY has a
potential to in situ reduce metal ions. Secondly, the surface
Figure 1 (a), (b) SEM, and (c), (d) TEM images of Pyr-GDY, showing a single Pyr-GDY
2
-1
nanofiber with an interlayer spacing (d-spacing) of 0.35 nm (insert 1d). (e) Raman area of Pyr-GDY with 3D network structure (SBET = 527 m g ,
spectrum of Pyr-GDY. (f) XPS pattern for C 1s of Pyr-GDY.
2
−1 47
Figure S8) is larger than that of GDY (SBET = 105 m g ). The
above results suggest that Pyr-GDY is a promising carbon
The morphology of as-prepared Pyr-GDY was characterized substrate for electroless deposition of metal catalysts, and
by scanning electron microscopy (SEM). As shown in Figure 1a, palladium was chosen as the candidate due to its wide range
densely packed nanofibers are distributed evenly over the of applications in various liquid-phase catalytic reactions.
entire surface of copper foil. The high-resolution SEM image
In a typical procedure, Pyr-GDY was simply dispersed in
(
Figure 1b) shows that the nanofibers are cross-linked in three water and mixed with K PdCl aqueous solution at 0 °C under
2
4
dimensions and form a network structure. The diameters of dark. After vigorously stirring for 30 min, the mixture was
nanofibers range from 3 to 10 nm. The HRTEM image of an centrifuged and washed with water for several times to obtain
individual nanofiber (Figure 1d) clearly shows curved streaks Pd/Pyr-GDY composite. XPS was performed to identify the
with a lattice parameter of 0.35 nm, which can be attributed to chemical state of Pd element in Pyr-GDY (Figure S9). The
the layer-to-layer distance of Pyr-GDY, and the XRD pattern of signals at 336.1 eV for Pd 3d5/2 and 341.4 eV for Pd 3d3/2
48
Pyr-GDY also shows a peak at 25.02°, corresponding to the clearly show the presence of Pd(0), indicating the elemental
interlayer spacing of 3.5 Å (Figure S5). We speculate that the Pd was successfully in-situ reduced and deposited on the
formation of ultrafine nanofibers originates from the stacking surface of Pyr-GDY nanofibers through a simple electroless
of small pieces of Pyr-GDY nanosheets in a linear fashion deposition process. The TEM image of Pd/Pyr-GDY (Figure 2a)
(Scheme 1). Due to the strong π-π stacking interactions shows no large aggregates of Pd particles, and its XRD pattern
between the pyrene rings, the stacking rate of small pieces of shows no diffraction peaks belonging to Pd (Figure S5),
Pyr-GDY nanosheets along the nanofiber direction is faster demonstrating the formation of well-dispersed Pd sub-
than the coupling reaction rate of TEP monomer along the 2D nanometric particles on the ultrafine Pyr-GDY nanofibers.5
Pyr-GDY nanosheets, thus small pieces of Pyr-GDY nanosheets High-angle annular dark-field scanning transmission electron
prefer to grow along the nanofiber direction to generate microscopy (HAADF-STEM) of Pd/Pyr-GDY reveals that Pd sub-
unique nanofibers rather than nanosheets. As a consequence, nanometric particles are well dispersed on the Pyr-GDY
numerous terminal uncoupled alkynes (Scheme 1) will remain substrate, with an average size around 0.83 nm (Figure 2b).
on the surface of Pyr-GDY nanofibers, which may act as the HAADF-STEM elemental mapping images of Pd/Pyr-GDY
binding sites for metal catalysts.
further confirm that Pd element is uniformly distributed on the
The chemical composition of Pry-GDY was investigated by Pyr-GDY substrate (Figures 2c-e).
Raman spectrum and X-ray photo-electron spectroscopy (XPS).
The Raman spectrum (Figure 1e) shows six obvious peaks at
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To further confirm the reduction and binding sites being the
View Article Online
DOI: 10.1039/C9TA03621K
terminal alkynyl groups in Pd/Pyr-GDY, we oxidized Pyr-GDY
using H
2 2
O to generate the oxidized sample of Pyr-GDYO.
Compared with conjugated diacetylene links, the terminal
50
alkynyl groups are much easier to be oxidized. The resulting
Raman spectrum of Pyr-GDYO is close to that of Pd/Pyr-GDY
(Figure 2f). However, the proportions of C−O and C=O bonds in
Pyr-GDYO are higher than those in Pd/Pyr-GDY (Table S1),
indicating the terminal alkynyl groups in Pd/Pyr-GDY may
partly oxidize by Pd(II), and unoxidized terminal alkynyl groups
may act as the binding sites for stabilizing the in-situ formed
Pd sub-nanometric particles. The binding energies of Pd 3d in
Pd/Pyr-GDY are lower than those of commercial Pd/C (Figure
S10), probably due to the electron-rich nature of terminal
alkynyl groups. In addition, the calculated binding energies
(
BE) between Pd(0) atom and Pd
4
cluster with various carbon
cluster
atoms in Pyr-GDY indicate that both Pd atom and Pd
4
prefer to bind to the terminal alkynyl group in Pyr-GDY,
resulting in the largest BE values of -38.98 kcal/mol for Pd(0)
atom (Figure S11) and -87.33 kcal/mol for Pd cluster (Figure
4
S12). The above results further demonstrate that terminal
alkynyl groups may serve as the reduction and binding sites for
Pd sub-nanometric particles. We believe that both the
structure of ultrafine nanofibers and the existence of terminal
alkynyl groups in Pyr-GDY are benefit to the formation and
stabilization of Pd sub-nanometric particles, demonstrating
Figure 2 (a) TEM, (b) HAADF-STEM images of Pd/Pyr-GDY, the bright parts in the white
circles represent Pd particles and (inset) the corresponding distribution of particle sizes.
(
c-e) HAADF-STEM elemental mapping images of Pd/Pyr-GDY. (f) Comparative Raman that Pyr-GDY is an ideal substrate for nucleation and growth of
spectra of Pyr-GDY, Pd/Pyr-GDY and Pyr-GDYO. (g) XPS pattern for C 1s of Pd/Pyr-GDY.
stable metallic sub-nanometric particles with “clean surface”
simply through an electroless deposition process, which can be
used as highly efficient SNCs.
Catalytic reduction of nitroarenes. The catalytic activity of
Pd/Pyr-GDY composite was evaluated by the reduction of
The interactions between Pd sub-nanometric particles and
Pyr-GDY. With successful deposition of Pd sub-nanometric
particles on Pyr-GDY substrate, the interactions between Pd
sub-nanometric particles and Pyr-GDY were investigated by
Raman and XPS spectra. As shown in Figure 2f, compared with
4
nitroarenes to arylamines using NaBH as a reductant in
aqueous solution, and the reduction of 4-nitrophenol (4-NP)
was firstly chosen as a model reaction. The reduction of 4-NP
can be monitored by ultraviolet-visible (UV-vis) spectroscopy.
-
1
Pyr-GDY, the Raman signal of Pd/Pyr-GDY at 1973.7 cm
almost disappears, while the peak at 2176.1 cm- still exists,
indicating the main reduction and binding sites are terminal
alkynyl groups, and the conjugated diacetylene links may not
interact with Pd(II), probably due to the strong π-π stacking
and hydrophobic interactions between the pyrene rings, which
prevent the hydrophilic Pd(II) salt to enter the interlayer of
Pyr-GDY. The C 1s XPS spectrum of Pd/Pyr-GDY shows that the
1
The aqueous solution of 4-NP and NaBH
peak at 400 nm due to the formation of 4-nitrophenolate ion
Figure S14). Upon the addition of Pd/Pyr-GDY composite, this
peak sharply decreased. Simultaneously, a new peak around
00 nm, which is the characteristic peak of 4-amionphenol (4-
4
exhibits an obvious
(
3
51
AP), appeared (Figure 3a). According to the pseudo-first-
order formula ln [C /C ] = kt, where C and C represent the
2
ratio of sp/sp decreases from 1:2 in Pyr-GDY to 1:2.5 in
t
0
t
0
Pd/Pyr-GDY, while the proportions of C−O and C=O bonds
increase in Pd/Pyr-GDY compared with those in Pyr-GDY (Table
S1), further demonstrating that the terminal alkynyl groups are
the reduction and binding sites for electroless deposition of Pd
sub-nanometric particles. A comparison of the XPS spectra of
Pd 3d in Pd/Pyr-GDY and commercial Pd/C shows that the
binding energies of Pd 3d3/2 (341.4 eV) and Pd 3d5/2 (336.1
eV) in Pd/Pyr-GDY are 0.4 eV lower than those in commercial
Pd/C (341.8 and 336.5 eV, Figure S10), suggesting that the
electron-rich Pyr-GDY substrate can donate more electrons to
Pd nanoparticles than activated carbon substrate in
concentrations of 4-NP at time t and 0 respectively, the
reaction rate constant k can be obtained by monitoring the
concentration changes of 4-NP. When Pd/Pyr-GDY, which had
the optimal Pd content (4.23%, Figure S15e), was added,
notably, the reduction of 4-NP was completed only within one
minute, and the reaction rate constant k was calculated to be
-1
3
.18 min (Figure 3), which is 9 times higher than that of
-1 29
reported Pd/GDYO (0.32 min ). To our knowledge, this value
is the highest among the documented Pd catalysts for the
4
reduction of 4-NP to 4-AP by NaBH (see Table S2). For
comparison, the catalytic activity of other carbon materials
based Pd composites was also evaluated by the reduction of 4-
NP under the same experimental condition (Figure S16, Figure
S17). The k values for Pd/GO, Pd/CNT, Pd/GDY, Pd/C and
49
commercial Pd/C, enduing Pd sub-nanometric particles
anchored on Pyr-GDY substrate a higher reduction catalytic
activity.
4
| J. Name., 2012, 00, 1-3
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Journal of Materials Chemistry A
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Pd/Pyr-GDYO with the same amount of Pd loading were
calculated to be 0.12, 0.15, 0.03, 0.01 and 1.59 min ,
respectively (Figures 3b and S14), 25, 21, 103, 300 and 2 times
higher than those of Pd/GO, Pd/CNT, Pd/GDY, commercial
Pd/C, and Pd/Pyr-GDYO respectively. TEM images show that
the Pd nanoparticles range from 3 to 40 nm in Pd/GO, Pd/CNT,
Pd/GDY and commercial Pd/C (Figure S19), much larger than
ARTICLE
View Article Online
DOI: 10.1039/C9TA03621K
-
1
Catalysts
Pd/Pyr-GDY
Pd/C
Yield/%
TON
TOF/h-1
18000
720
100
4
90000
3600
that in Pd/Pyr-GDY. The BE between Pd
and sp -hybrid carbon material also show that Pd
4
cluster with Pyr-GDY
2
4
cluster is
Pd/CNT
Pd/GO
8
7200
1400
2
much stable on Pyr-GDY (BE = -83.33 kcal/mol) than it on sp -
hybrid carbon (BE = -32.99 kcal/mol) (Figure S12, S13). In
addition, Pd/Pyr-GDY can also catalyze the reduction of other
nitroarenes (2-nitrophenol, 4-nitrobenzoic acid, 4-nitrobenzyl
alcohol, 4-nitroaniline, 3-nitroaniline and 2-nitroaniline, Figure
30
27000
5400
Reaction conditions: bromobenzene (1.0 mmol), phenylboronic acid (1.5 mmol),
Na PO ·12H O (2.0 mmol), EtOH/H O (1:1; 10 mL), Pd/Pyr-GDY and other Pd
composites (1.1 × 10 mmol Pd). The suspension was stirred under N for 5 hours
3
4
2
2
-5
2
S18), achieving the extremely high rate constants ranged from at 80 °C.
-1
3
.24 to 46.81 min , demonstrating the outstanding catalytic
Table 2. Suzuki-Miyaura reaction with various reactants.a
activity of Pd/Pyr-GDY towards the reduction of these
nitroarenes.
Entry
R
1
R
2
Time/h TOF/h-1
Yield/%b
>99.9
>99.9
>99.9
>99.9
>99.9
>99.9
>99.9
>99.9
>99.9
>99.9
1
2
3
4
5
6
7
8
9
10
H
H
5
1
3
1
5
3
10
7
6
2
18000
90000
30000
90000
18000
30000
9000
H
CH
H
3
3
3
3
3
OH
OH
OCH
OCH
CH
H
Figure 3 (a) Time-dependent UV-vis absorption spectra recorded during the
catalytic reduction of 4-nitrophenol by Pd/Pyr-GDY. (b) Plots of ln (C /C ) as a
t 0
function of the reaction time for the reduction of 4-nitrophenol catalyzed by
Pd/Pyr-GDY, Pd/GO, Pd/CNT, Pd/GDY and commercial Pd/C, respectively.
3
3
CH
H
OCF
3
Catalytic Suzuki-Miyaura reactions
.
Besides catalytic
OCF
3
CH
H
12857
15000
45000
reduction of nitroarenes, we also investigate the catalytic
performance of Pd/Pyr-GDY composite for Suzuki-Miyaura
reaction between bromobenzene and phenylboronic acid. The
Suzuki-Miyaura reaction represents one of the most important
carbon-carbon coupling reactions in organic synthesis, and Pd
catalysts possess the highest catalytic activity to catalyze these
COCH
COCH
3
3
CH
aReaction conditions: bromobenzene (1.0 mmol), phenylboronic acid (1.5 mmol),
Na PO ·12H O (2.0 mmol), EtOH/H
O (1:1, 10 mL), Pd/Pyr-GDY (1.1 × 10-5 mmol
at 80 °C; bYields were determined by
Pd). The suspension was stired under N
3
4
2
2
2
reactions, while so far few Pd catalysts show high catalytic HPLC.
1
0-11,52-53
performance with ppm levels of Pd.
In our
To illustrate the substrate tolerance of Pd/Pyr-GDY SNC, we
examined the carbon-carbon coupling reactions for a series of
derivatives of bromobenzene and phenylboronic acids. As
shown in Table 2, high catalytic activities were also observed
for the substrates with both electron-rich and electron-poor
substituents. The corresponding biphenyl products were
obtained in more than 99.9% yields, with the TOF values of
investigations, 11 ppm Pd containing of Pd/Pyr-GDY composite
was used. Notably, the conversion of the reaction is almost
1
00% within 5 hours, with high TON and TOF values of 90000
-
1
and 18000 h , respectively (Table 1). For comparison, the
catalytic performances of other Pd composites (11 ppm Pd
content) including commercial Pd/C (5 wt%), Pd/CNT and
Pd/GO were also evaluated under the same condition, while
only 4%, 8% and 30% conversion were obtained, respectively
-1
9
000–90000 h . Furthermore, the durability of Pd/Pyr-GDY
was tested by circulation experiments of Suzuki-Miyaura
reaction using bromobenzene and phenylboronic acid as the
reactants. The yield maintains 96.8% after five cycles (Figure
S20), and no noticeable changes in the Pd particle sizes,
(
Table 1). The TON and TOF values for Pd/Pyr-GDY are 25, 12.5
and 3.3-fold higher than those of commercial Pd/C, Pd/CNT
and Pd/GO, respectively.
Table 1. The catalytic performance of Pd composites for Suzuki-Miyaura valence state and the morphology of Pd/Pyr-GDY were
reaction.
observed in the TEM images and XPS measurement (Figures
S21 and S22), indicating Pd/Pyr-GDY composite is a durable
This journal is © The Royal Society of Chemistry 20xx
J. Name., 2013, 00, 1-3 | 5
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Journal of Materials Chemistry A
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Journal Name
SNC, and Pyr-GDY can act as an excellent substrate to stabilize mg/mL) was mixed with 40 µL, 80 µL, 120 µL, 160 µL, 200 µL,
View Article Online
DOI: 10.1039/C9TA03621K
280 µL, and 400 µL of K PdCl (2.3 mM) aqueous solution,
2 4
the sub-nanometric metal catalysts.
respectively, under vigorous stirring for 30 min in an ice bath.
The reaction mixture was then centrifuged and washed with
water for several times to remove the remaining reagents.
Conclusions
In conclusion, a novel terminal alkynyl group rich graphdiyne Synthesis of Pd Loaded on Other Substrates. In a typical
ultrafine nanofiber of Pyr-GDY was constructed, which can be synthesis, a homogeneous aqueous dispersion of GO, CNT, or
used as an ideal substrate for nucleation and growth of stable GDY (2 mL, 0.5 mg/mL) was respectively mixed with 200 µL of
sub-nanometric metal particles with “clean surface”. Simply by K PdCl (2.3 mM) aqueous solution under vigorous stirring for
2
4
an electroless deposition process, a Pd/Pyr-GDY composite 30 min in an ice bath. Then, the reaction mixture was
containing sub-nanometric Pd particles, with an average centrifuged and washed with water to remove unreacted
diameter of only 0.83 nm, was successfully obtained. reagents. The resulting products are denoted as Pd/GO,
Benefiting from its ultrasmall Pd nanoparticles with “clean Pd/CNT, Pd/GDY, respectively.
surface”, the electron-rich nature of terminal alkynyl groups,
Catalytic Reduction of Nitroarenes. The aqueous solution of
as well as the unique three-dimensional network structure of
4
NaBH (0.65 mL, 0.2 M) and corresponding nitroarenes (0.10
Pyr-GDY which is favor for rapid mass transfer, Pd/Pyr-GDY
composite displays extremely high catalytic activity for the
reduction of nitroarenes, as well as the Suzuki–Miyaura
reactions with ppm amounts of Pd. The unique nanostructure
of Pyr-GDY makes its bright prospects for in-situ generation of
other stable metal SNCs with “clean surface” for various
catalytic reactions, this investigation is ongoing in our lab.
mL, 1 mM) were mixed with water (2.25 mL). Then the
homogenous dispersion of Pd/Pyr-GDY, Pd/GO, Pd/CNT,
Pd/GDY, Pd/C was added, respectively, the adsorption spectra
of the resulting solution was monitored by recording the UV-
Vis spectra at short intervals in the range 250–500 nm at room
temperature.
Catalytic Suzuki-Miyaura Reactions. In a round-bottomed flask
equipped with a condenser and a magnetic stirrer was added
aryl bromide (1.0 mmol), arylboronic acid (1.5 mmol),
Experimental section
Synthesis of Pyr-GDY. 1,3,6,8-Tetrakis((trimethysilyl)ethynyl)-
pyrene (TEP-TMS) was synthesized by a literature method,33
Na
3 4 2 2
PO ·12H O (2.0 mmol), EtOH/H O (1:1, 10 mL), Pd/Pyr-GDY
-5
(1.1 × 10 mmol Pd), respectively. The suspension was allowed
to stir under N
by HPLC.
2
at 80 °C for 5 hours. The product was analyzed
its purity was confirmed by the NMR and ESI-MS
1
measurements. H NMR (400 MHz, CDCl
3
, δ) 8.61 (s, 4H), 8.32
) δ 134.44,
31.94, 126.90, 123.51, 118.55, 102.69, 101.36, 0.93 ppm.
(
1
s, 2H), 0.38 ppm (s, 36H). 13C NMR (100 MHz, CDCl
3
Conflicts of interest
There are no conflicts to declare.
+
+
+
4
HRMS (ESI) m/z [M + H ] . Anal. calcd for C36H43Si 587.2442,
found 587.2421.
Pyr-GDY was synthesized by the following procedure. To a
0 mL THF solution containing 100 mg (0.17 mmol) TEP-TMS,
.0 mL of TBAF (1 M in THF, 1.0 mmol) was added under argon
5
1
Acknowledgements
atmosphere. The mixture was stirred at 0 °C for 10 min, then This work was financially supported by National Key R&D
diluted with ethyl acetate, and washed three times with Program of China (2017YFA0700104), NSFC (21790052,
saturated NaCl and dried by anhydrous Na SO . Finally, the 21702146, 21805207 and 21331007) and 111 Project of China
2 4
solvent was evaporated under vacuum to obtain the (D17003).
desilicated product of TEP monomer. The obtained yellow TEP
was dissolved in 75 mL of pyridine and added dropwise into a
three-necked flask containing pyridine (150 mL) and copper Notes and references
foils within 12 h. The reaction mixture was kept at 110 °C for
three days under darkness and argon atmosphere. Ultimately,
the Pyr-GDY was grown on the surface of copper foils and
isolated by ultrasonic method. The Pyr-GDY powder was
washed with hot N, N’-dimethylformamide (DMF) and acetone
sequentially to remove unreacted TEP monomer and
oligomers, and then dried at 50 °C under vacuum overnight.
1
. L. Liu and A. Corma, Chem. Rev., 2018, 118, 4981-5079.
2. B. Yoon, H. Hakkinen, U. Landman, A. S. Worz, J. M. Antonietti,
S. Abbet, K. Judai and U. Heiz, Science, 2005, 307, 403-407.
3. B. Ni and X. Wang, Chem. Sci., 2016, 7, 3978-3991.
4
5
. B. Ni, Y. Shi and X. Wang, Adv. Mater., 2018, 30, 1802031.
. X. Yang, J.-K. Sun, M. Kitta, H. Pang and Q. Xu, Nat. Catal., 2018,
1, 214-220.
6. R. J. White, R. Luque, V. L. Budarin, J. H. Clark and D. J.
Synthesis of Pyr-GDYO. Pyr-GDY powder (5 mg) was dispersed
Macquarrie, Chem. Soc. Rev., 2009, 38, 481-494.
in 15 mL 30% H
2
O
2
, followed by vigorous stirring at room
7. D. Astruc, F. Lu and J. R. Aranzaes, Angew. Chem., Int. Ed. Engl.,
2005, 44, 7852-7872.
8. M.-P. Pileni, Nat. Mater., 2003, 2, 145.
temperature for 5 h. The resulting powder was filtered and
washed with water.
9. H. Wang, J.-G. Wang, Z.-R. Shen, Y.-P. Liu, D.-T. Ding and T.-H.
Synthesis of Pd/Pyr-GDY. In
a
typical synthesis,
a
Chen, J. Catal., 2010, 275, 140-148.
homogeneous aqueous dispersion of Pyr-GDY (2 mL, 0.5
6
| J. Name., 2012, 00, 1-3
This journal is © The Royal Society of Chemistry 20xx
Please do not adjust margins

Please do not adjust margins
Page 7 of 8
Journal of Materials Chemistry A
Journal Name
ARTICLE
1
0. C. Wang, R. Ciganda, L. Salmon, D. Gregurec, J. Irigoyen, S.
Moya, J. Ruiz and D. Astruc, Angew. Chem., Int. Ed. Engl., 2016,
Gao, C. Chen, L. Tong, J. Zhang and Z. Liu, Adv. MVaiteewr.A,rt2ic0le1O7n,l2in9e,
1700421.
DOI: 10.1039/C9TA03621K
5
5, 3091-3095.
1. S. Ogasawara and S. Kato, J. Am. Chem. Soc., 2010, 132, 4608-
613.
41. J. Zhou, X. Gao, R. Liu, Z. Xie, J. Yang, S. Zhang, G. Zhang, H. Liu,
Y. Li, J. Zhang and Z. Liu, J. Am. Chem. Soc., 2015, 137, 7596-
7599.
1
1
1
1
4
2. O. M. Wilson, R. W. J. Scott, J. C. Garcia-Martinez and R. M.
Crooks, J. Am. Chem. Soc., 2005, 127, 1015-1024.
3. C. Deraedt, N. Pinaud and D. Astruc, J. Am. Chem. Soc., 2014,
42. X. Gao, Y. Zhu, D. Yi, J. Zhou, S. Zhang, C. Yin, F. Ding, S. Zhang,
X. Yi, J. Wang, L. Tong, Y. Han, Z. Liu and J. Zhang, Sci. Adv.,
2018, 4, eaat6378.
43. K. Ihm, T.-H. Kang, D. H. Lee, S.-Y. Park, K.-J. Kim, B. Kim, J. H.
Yang and C. Y. Park, Surf. Sci., 2006, 600, 3729-3733.
44. H. Estrade-Szwarckopf, Carbon, 2004, 42, 1713-1721.
45. H. Reiss and A. Heller, J. Phys. Chem., 1985, 89, 4207-4213.
46. J. Li, X. Gao, B. Liu, Q. Feng, X. B. Li, M. Y. Huang, Z. Liu, J.
Zhang, C. H. Tung and L. Z. Wu, J. Am. Chem. Soc., 2016, 138,
3954-3957.
1
36, 12092-12098.
4. K. J. Si, Y. Chen, Q. Shi and W. Cheng, Adv. Sci., 2018, 5,
700179.
1
1
1
1
5. R. B. Grubbs, Polym. Rev., 2007, 47, 197-215.
6. Z. Niu and Y. Li, Chem. Mater., 2013, 26, 72-83.
7. X. Chen, G. Wu, J. Chen, X. Chen, Z. Xie and X. Wang, J. Am.
Chem. Soc., 2011, 133, 3693-3695.
1
8. L. Qu, L. Dai and E. Osawa, J. Am. Chem. Soc., 2006, 128, 5523-
47. R. Liu, J. Zhou, X. Gao, J. Li, Z. Xie, Z. Li, S. Zhang, L. Tong, J.
Zhang and Z. Liu, Adv. Electron. Mater., 2017, 3, 1700122.
48. Z. Li, X.-C. Yang, N. Tsumori, Z. Liu, Y. Himeda, T. Autrey and Q.
Xu, ACS Catal., 2017. 7, 2720–2724.
49. C.-H. Hao, X.-N. Guo, Y.-T. Pan, S. Chen, Z.-F. Jiao, H. Yang and
X.-Y. Guo, J. Am. Chem. Soc., 2016, 138, 9361-9364.
50. L. Zhang, Acc. Chem. Res., 2014, 47, 877-888.
51. H. Liu, Z. Feng, J. Wang, L. Zhang and D. Su, Catal. Today, 2016,
260, 55-59.
5532.
1
2
9. L. Qu and L. Dai, J. Am. Chem. Soc., 2005, 127, 10806-10807.
0. H. C. Choi, M. Shim, S. Bangsaruntip and H. Dai, J. Am. Chem.
Soc., 2002, 124, 9058-9059.
2
2
2
2
2
2
1. G. Li, Y. Li, H. Liu, Y. Guo, Y. Li and D. Zhu, Chem. Commun.,
2
010, 46, 3256-3258.
2. Y. Xue, B. Huang, Y. Yi, Y. Guo, Z. Zuo, Y. Li, Z. Jia, H. Liu and Y. Li,
Nat. Commun., 2018, 9, 1460.
3. X.-P. Yin, H.-J. Wang, S.-F. Tang, X.-L. Lu, M. Shu, R. Si and T.-B.
Lu, Angew. Chem., Int. Ed., 2018, 57, 9382-9386.
4.Y.-Y. Han, X.-L. Lu, S.-F. Tang, X.-P. Yin, Z.-W. Wei and T.-B. Lu, Adv.
Energy Mater., 2018, 8, 1702992.
52. N. Miyaura and A. Suzuki, Chem. Rev., 1995, 95, 2457-2483.
53. S. Handa, Y. Wang, F. Gallou and B. H. Lipshutz, Science, 2015,
349, 1087-1091.
5. C. Huang, Y. Li, N. Wang, Y. Xue, Z. Zuo, H. Liu and Y. Li, Chem.
Rev., 2018, 118, 7744-7803.
6. S. Guo, H. Yan, F. Wu, L. Zhao, P. Yu, H. Liu, Y. Li and L. Mao,
Anal. Chem., 2017, 89, 13008-13015.
2
7. S. Guo, Y. Jiang, F. Wu, P. Yu, H. Liu, Y. Li and L. Mao, ACS Appl.
Mater. Interfaces, 2019, 11, 2684-2691.
2
2
3
8. H. Yan, P. Yu, G. Han, Q. Zhang, L. Gu, Y. Yi, H. Liu, Y. Li and L.
Mao, Angew. Chem., Int. Ed., 2019, 58, 746-750.
9.H. Qi, P. Yu, Y. Wang, G. Han, H. Liu, Y. Yi, Y. Li and L. Mao, J. Am.
Chem. Soc., 2015, 137, 5260-5263.
0.Y. Zhao, J. Wan, H. Yao, L. Zhang, K. Lin, L. Wang, N. Yang, D. Liu,
L. Song, J. Zhu, L. Gu, L. Liu, H. Zhao, Y. Li and D. Wang, Nat.
Chem., 2018, 10, 924-931.
3
3
3
1. C. Wang, P. Yu, S. Guo, L. Mao, H. Liu and Y. Li, Chem. Commun.,
2
016, 52, 5629-5632.
2. H. Yan, S. Guo, F. Wu, P. Yu, H. Liu, Y. Li and L. Mao, Angew.
Chem., Int. Ed., 2018, 57, 3922-3926.
3. F. Xu, T. Nishida, K. Shinohara, L. Peng, M. Takezaki, T. Kamada,
H. Akashi, H. Nakamura, K. Sugiyama, K. Ohta, A. Orita and J.
Otera, Organometallics, 2017, 36, 556-563.
34. T. Zhang, Y. Du, F. Müller, I. Amin and R. Jordan, Polym. Chem.,
2
015, 6, 2726-2733.
3
5. T. Zhang, Y. Du, J. Kalbacova, R. Schubel, R. D. Rodriguez, T.
Chen, D. R. T. Zahn and R. Jordan, Polym. Chem., 2015, 6, 8176-
8
183.
6. Y.-N. Li, J.-L. Wang and L.-N. He, Tetrahedron Lett., 2011, 52,
485-3488.
7.P. Siemsen, R. C. Livingston and F. Diederich, Angew. Chem., Int.
3
3
3
Ed. Engl., 2000, 39, 2632-2657.
8. C. Liu, X. Zhang, L. Li, J. Cui, Y. E. Shi, L. Wang and J. Zhan,
Analyst, 2015, 140, 4668-4675.
9. J. Neugebauer, E. J. Baerends, E. V. Efremov, F. Ariese and C.
Gooijer, J. Phys. Chem. A., 2005, 109, 2100-2106.
0. J. Li, Z. Xie, Y. Xiong, Z. Li, Q. Huang, S. Zhang, J. Zhou, R. Liu, X.
3
3
4
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Journal of Materials Chemistry A
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View Article Online
DOI: 10.1039/C9TA03621K
A Graphdiyne-Based Carbon Material for Electroless Deposition and Stabilization of
Sub-Nanometric Pd Catalysts with Extremely High Catalytic Activity
†
†
Liang-Liang Yang, Hong-Juan Wang, Juan Wang, Yu Li, Wen Zhang* and Tong-Bu Lu*
KEYWORDS: graphdiyne, electroless deposition, palladium sub-nanometric catalyst, nitroarenes reduction, Suzuki coupling reactions
SYNOPSIS
A new graphdiyne-based carbon material was synthesized as an ideal substrate for electroless deposition and stabilization of sub-nanometric
Pd catalyst, which showed extremely high catalytic activities for the reduction of nitroarenes and Suzuki coupling reactions.