Supporting Materials
Palladium nanoparticles supported on a triptycene-based
microporous polymer: Highly active catalysts for CO oxidation
Qian Liang, a Jian Liu,
a Yuechang Wei,
a Zhen Zhao*a
and Mark MacLachlan*b
a: State Key Laboratory of Heavy Oil Processing, China University of Petroleum,
Beijing 102249, China.
b: Department of Chemistry, University of British Columbia, Vancouver, BC, V6T
1Z1, Canada.
Electronic Supplementary Material (ESI) for Chemical CommunicationsThis journal is © The Royal Society of Chemistry 2013
Materials and Characterization
2,7,14-Tribromotriptycene was prepared by a literature procedure.1-2
Other reagents
were obtained from standard suppliers. Powder X-ray diffraction was measured with a
Shimadzu XRD 6000 using Ni-filtered Cu Kα (λ = 0.15406 nm) radiation operating at
40 kV and 10 mA. The surface morphology of the catalyst was observed by field
emission scanning electron microscopy (FESEM) on a Quanta 200F instruments using
accelerating voltages of 5 kV. Samples for SEM were dusted on an adhesive
conductive carbon belt attached to a copper disk and were coated with 10 nm Au prior
to measurement. The TEM and HRTEM images were carried out at an accelerating
voltage of 200 kV using a JEOL JEM 2100 electron microscope equipped with a field
emission source. Fourier transform infrared spectroscopy (FT-IR) spectra were
obtained on a FTS-3000 spectrophotometer manufactured by American Digilab
company. The measured wafer was prepared as a KBr pellet with the weight ratio of
sample to KBr, 1/100. Specific surface area was measured by adsorption-desorption
of N2 gas at 77 K with Micromeretics ASAP 2000 instrument. Brunauer-Emmett-
Teller (BET) method was utilized to calculate the specific surface areas from the
adsorption data. Before the measurements, the samples were outgassed at 120 ºC for
10 h. The surface area of the polymer noticeably decreased after Pd loading. X-ray
photoelectron spectra (XPS) were recorded on a Perkin-Elmer PHI-1600 ESCA
spectrometer using Mg Kα (hv = 1253.6 eV, 1 eV = 1.603 × 10-19
J) X-ray source.
The actual content of palladium supported on NTP was determined by inductively
coupled plasma atomic emission spectrometry (ICP-AES) (PE, OPTIMA 5300DV).
The 13
C CP/MAS NMR spectra were recorded with the contact time of 2 ms (ramp
100) and pulse delay of 3 s. TGA data was obtained using a Perker Elmer TGA6
instrument.
Synthesis of NTP
1,5-Cyclooctadiene (cod, 900 μL, 7.35 mmol) was added to a solution of
2,7,14-tribromotriptycene (1 g, 2 mmol), bis(1,5-cyclooctadiene)nickel(0) (2 g,
7.35mmol) and 2,2’-bipyridyl (1.15 g, 7.35 mmol) in dehydrated DMF (15 mL), and
the mixture was heated at reflux (85 °C) under N2 for 96 h. After cooling the mixture
to room temperature, concentrated hydrochloric acid (36.5-38.0%) was added. The
precipitate was isolated by filtration and washed with CHCl3, THF and DCM,
respectively, and dried overnight to give the product (0.44 g, 85%) as an off-white
solid. Elemental analysis for C20H11: Calcd. C, 95.59; H, 4.41. Found: C, 94.21; H,
4.02.
Electronic Supplementary Material (ESI) for Chemical CommunicationsThis journal is © The Royal Society of Chemistry 2013
Synthesis of Pd/NTP
An aqueous solution of H2PdCl4 (10 mg mL-1
) was added dropwise to the NTP
support under vigorous agitation for 10 min. The suspension was subjected to
sonication (100 W, 40 kHz) at 25 °C for 3 h to mix the palladium precursor and
porous support NTP evenly. The mixture solution was driven by a peristaltic pump
(Baoding Lange Co., Ltd.) at a rotation speed of 200 rpm (~360 mL min-1
) to form a
tubal cycling flow. A reductant solution (NaBH4) (1 mg mL-1
, 1 mL min-1
) was
injected into the membrane reactor with two ceramic membrane tubes (φ = 3mm ×
160 mm, Hyflux Group of Companies, Singapore) by a constant flow pump
(HLB-2020, Satellite Manufactory of Beijing). At the same time, hydrogen gas was
also flowed through the membrane rector with the other two membrane tubes. The
metal precursor solution flowed inside the glass tube reactor and outside the ceramic
tubes. The NaBH4 solution was infiltrated through the abundant holes (d = 40 nm) on
the wall of the ceramic tubes into the glass tube reactor, where the reduction of metal
ions occurred immediately when the two solutions met. The hydrogen
bubbling-assisted stirring operation (40 mL min-1
) was developed to vigorously stir
the solution and to make the reaction homogenous. The synthesis process was stopped
after complete consumption of the NaBH4 solution. The reaction system was further
vigorously bubbled with hydrogen gas for 1 h and then kept static for 1 h. Then, the
product was filtered and washed with distilled water until the Cl-
was completely
removed according to a test with AgNO3, and the final products were dried in an oven
at 60 °C overnight and the desired Pd/NTP catalysts were obtained.
Figure S1. Digital photos of GBMR device. The right photo is the ceramic membrane
reactor composed of four ceramic membrane tubes, which is the core of the device of
GBMR method.
Electronic Supplementary Material (ESI) for Chemical CommunicationsThis journal is © The Royal Society of Chemistry 2013
Catalytic reaction
The CO catalysis measurements were performed in a fixed-bed tubular quartz
system (φ = 8 mm) under ambient pressure. The reaction temperature was controlled
through a PID regulation system based on the measurements of a K-type
thermocouple and varied from 20 °C to 400 °C. Reactant gases (50 mL min-1
)
containing 1 vol% CO, 21 vol% O2 and 78 vol% Ar were passed through the catalyst
bed (0.05 g). Temperature was increased linearly at 5 °C min-1
, and remained at every
measured temperature point for 30 min to analyze the gas composition. The inlet and
outlet gas compositions were analyzed with an online gas chromatograph (GC,
Sp-3420, Beijing) by using FID detectors. The catalytic activity was evaluated on the
basis of CO conversion, which was calculated with the CO concentration in the
reactant gas and in the effluent gas at each temperature point. We calculated CO
conversion for each data point as follows: CO conversion (%) = {1 –
([CO]/([CO]+[CO2]))}*100
Electronic Supplementary Material (ESI) for Chemical CommunicationsThis journal is © The Royal Society of Chemistry 2013
Supporting Characterization Data
0 100 200 300 400 500 600 700 800
0
10
20
30
40
50
60
70
80
90
100
Wei
gh
t lo
ss (
%)
Temperture ( oC)
Figure S2. (a) SEM image of NTP; (b) TEM image of NTP; (c) TGA of NTP under
nitrogen atmosphere.
(a) (b)
(c)
Electronic Supplementary Material (ESI) for Chemical CommunicationsThis journal is © The Royal Society of Chemistry 2013
3 4 5 6 70
5
10
15
20
25
Fre
qu
en
cey %
d (n)
1 2 3 4 50
5
10
15
20
25
30
35
Fre
qu
en
cey %
d (n)
1 2 3 4 50
5
10
15
20
25
30
35
Fre
qu
en
cey %
d (n)
Figure S3. TEM images and size distribution of 4.5 wt% (a, b, c), 2.2 wt% (d, e, f)
and 0.9 wt% (g, h, i) Pd/NTP
(a) (b) (c)
(d) (e) (f)
(g) (h) (i)
Electronic Supplementary Material (ESI) for Chemical CommunicationsThis journal is © The Royal Society of Chemistry 2013
1200 1100 1000 900 800 700 600 500 400
Tra
nsm
itta
nce
/ a
.u.
Wavenumber ( cm-1)
NTP
Pd/NTP (3.2 nm)
Pd/NTP ( 5.0 nm)
Figure S4. FT-IR spectra of (a) NTP, (b) 3.0 wt% Pd/NTP (3.2 nm) and (c) 4.5 wt %
Pd/NTP (5.0 nm). The shift of the peak is nearly unchanged after Pd particles are
loaded on the NTP support.
10 20 30 40 50 60
◆
Inte
ns
ity
2 theta
NTP support
Pd/NTP
Pd/NTP after catalysis
◆
Pd (111)
Figure S5. Powder XRD patterns of NTP samples: (a) NTP, (b) Pd/NTP before CO
oxidation, (c) Pd/NTP after CO oxidation.
(a)
(b)
(c)
(a)
(b)
(c)
35 40 45 50
Electronic Supplementary Material (ESI) for Chemical CommunicationsThis journal is © The Royal Society of Chemistry 2013
0 200 400 600 800
C 1sO 1s
O 1s
C 1s
Inte
nsi
ty (
CP
S)
Binding energy (eV)
NTP
Pd/NTP
Pd 3d
530 535 540 545
Inte
nsi
ty (
CP
S)
Binding energy (eV)
Pd/NTP
NTP
532.6
531.4
O1s
(a)
(b)
Electronic Supplementary Material (ESI) for Chemical CommunicationsThis journal is © The Royal Society of Chemistry 2013
330 332 334 336 338 340 342 344 346
Inte
nsi
ty (
CP
S)
Binding energy (eV)
335.6
340.8
Pd 3d
Figure S6. XPS spectra of the NTP and Pd/NTP, (a) survey of the sample, (b) O 1s
and (c) Pd 3d.
(c)
Electronic Supplementary Material (ESI) for Chemical CommunicationsThis journal is © The Royal Society of Chemistry 2013
Table S1. Surface area measurements for the blank NTP and Pd/NTP samples.
Median pore width based on Horvath-Kawazoe equation.
Sample BET surface area
(m2 g
-1)
Langmuir surface
area (m2 g
-1)
Total pore
volume (cm3 g
-1)
Pore width
(nm)
NTP 1502 2031 1.16 0.72
0.9 wt% Pd/NTP 1039 1434 0.85 0.70
2.2 wt% Pd/NTP 843 1129 0.54 0.71
3.0 wt% Pd/NTP 1029 1365 0.69 0.72
4.5 wt% Pd/NTP 701 953 0.42 0.70
0.0 0.2 0.4 0.6 0.8 1.0
0
200
400
600
800
1000
1200
Vo
lum
n A
bs
orb
ed
(cm
3g
-1)
Relative Pressure(P/P0)
NTP (support)
3.0 wt% Pd/NTP
3.0 wt% Pd/NTP after catalysis
Figure S7. Nitrogen adsorption isotherms of NTP and 3.0 wt% Pd/NTP samples
before and after CO oxidation measured at 77 K. HK pore size distribution of pure
NTP. Empty symbols represent the desorption isotherms.
0 1 2 3 4
(dV
/dW
)/(c
m3g
-1 n
m-1
)
Pore width / nm
0.37 nm
NTP
Electronic Supplementary Material (ESI) for Chemical CommunicationsThis journal is © The Royal Society of Chemistry 2013
40 60 80 100 120 140 160 180 200 220 240 260
0
20
40
60
80
100
CO
con
ver
sion
(%
)
Temperature ( oC)
0.9 wt % Pd/NTP (2.7 nm)
2.2 wt % Pd/NTP (3.0 nm)
3.0 wt % Pd/NTP (3.2 nm)
4.5 wt % Pd/NTP (5.0 nm)
NTP support
40 60 80 100 120 140 160 180
0
20
40
60
80
100
CO
con
ver
sion
(%
)
Temperature ( oC)
after 1 run of catalysis
after 2 run of catalysis
after 3 run of catalysis
after 4 run of catalysis
after 5 run of catalysis
Figure S8. (a) Conversion-temperature curves for CO oxidation over Pd/NTP
catalysts with different Pd loadings and (b) over 3.0 wt% Pd/NTP (3.2 nm) for
repeated catalytic runs.
(a)
(b)
Electronic Supplementary Material (ESI) for Chemical CommunicationsThis journal is © The Royal Society of Chemistry 2013
3 4 5 6 7 8
0
5
10
15
20
Fre
qu
en
cey %
d (n)
4.5 wt% Pd/NTP
after catalysis
Mean size 5.1 nm
2 3 4 5 6
0
5
10
15
20
25
30
Fre
qu
en
cey %
d (n)
3.0 wt% Pd/NTP
after catalysis
Mean size 3.5 nm
Figure S9. TEM images of the used 4.5 wt% (a), 3.0 wt% (c) Pd/NTP and
corresponding Pd NPs size distributions in 4.5 wt% (b), 3.0 wt% (d) Pd/NTP
2.1 2.2 2.3 2.4 2.5 2.6 2.7
2
3
4
5
6
7
8
Pd/NTP (3.2 nm)
Pd/NTP (5.0 nm)
Pd/COP-4-DE
In (
Re
ac
tio
n r
ate
× 1
05)
(m
mo
l COg
-1
cata
lysts
-1)
1000/T(K-1)
Figure S10. Arrhenius plots for the reaction activation energy on 3.0 wt% Pd/NTP
(3.2 nm), 4.5 wt% Pd/NTP (5.0 nm) and Pd/COP-4-DE.
(a)
(c)
(b)
(d)
Electronic Supplementary Material (ESI) for Chemical CommunicationsThis journal is © The Royal Society of Chemistry 2013
Reference
1 J. H. Chong and M. J. MacLachlan, Inorg. Chem., 2006, 45, 1442.
2 C. Zhang and C. -F. Chen, J. Org. Chem., 2006, 71, 6626.
Electronic Supplementary Material (ESI) for Chemical CommunicationsThis journal is © The Royal Society of Chemistry 2013