Supporting Materials · outlet gas compositions were analyzed with an online gas chromatograph (GC,...

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.


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.


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


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)


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)


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


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)


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)


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


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





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)


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)


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.


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