SUPPORTING INFORMATION Mesoporous multiwalled carbon ...

Electronic Supplementary Material (ESI) for Journal of Materials Chemistry A This journal is © The Royal Society of Chemistry 2012

SUPPORTING INFORMATION Mesoporous multiwalled carbon nanotubes as supports for monodispersed iron–boron catalysts: Improved hydrogen generation from hydrous hydrazine decomposition Dong Ge Tong,* a,b Wei Chu,*c , Ping Wu, a,b Gui Fang Gu, a,b and Li Zhang a,b a

Mineral Resources Chemistry Key Laboratory of Sichuan Higher Education

Institutions, College of Materials and Chemistry & Chemical Engineering, Chengdu University of Technology, Chengdu 610059, China. E-mail: [email protected]; Fax: +86-28-8407 9074 b

Institute of green catalysis and synthesis, College of Materials and Chemistry &

Chemical Engineering, Chengdu University of Technology, Chengdu 610059, China c

College of Chemical Engineering, Sichuan University, Chengdu 610065, China.

E-mail: [email protected] ; Fax: +86-28-8540 3397 Summary: 14 Pages; 2 Tables; 17 Figures;

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Table S1 Effect of the amount of NaOH additive on the catalytic activity and selectivity of 0.5g 9.86wt.% Fe-B/MWCNTs during the decomposition of 200mL 0.5molL-1 aqueous N2H4 solution Molar ratio of NaOH / N2H4

H2 generation rate/ Lh-1g-1catalyst

Rm/ mol h-1g-1 Fe

TOF/ H2 selectivity/% s-1

0 0.05 0.1 0.2 0.5 1 2

34.2 34.3 34.4 34.7 34.9 34.9 34.9

8.75 8.75 8.75 8.75 8.75 8.75 8.75

1.12 1.12 1.12 1.12 1.12 1.12 1.12

97.0 97.2 97.5 98.4 99.1 99.1 99.1

Table S2 Effect of the temperature on the catalytic activity and selectivity of 0.5g 9.86wt.% Fe-B/MWCNTs during the decomposition of 200mL 0.5 molL-1 aqueous N2H4 solution Temperature / K

H2 generation rate/ Lh-1g-1catalyst

Rm/ molh-1g-1Fe

TOF/ s-1

H2 selectivity/%

293 303 313 323 333

34.2 64.5 116.5 202.9 342.1

8.75 16.5 29.8 51.9 87.5

1.12 2.11 3.81 6.64 11.2

97.0 97.0 97.0 97.0 97.0

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Fig.S1 Pore size distribution curves of (a) MWCNTs, (b) 3.33wt.% Fe–B/MWCNTs, (c) 6.74wt.%

Fe–B/MWCNTs,

(d)

9.86wt.%

Fe–B/MWCNTs,

Fe–B/MWCNTs and (f) 20.65wt.% Fe–B/MWCNTs.

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(e)

13.50wt.%


(a)

(b)

(c)

(d)

(e)

(f)

(g)

Fig.S2 TEM images of (a) MWCNTs, (b) 3.33wt.% Fe–B/MWCNTs, (c) 6.74wt.% Fe–B/MWCNTs, (d) 9.86wt.% Fe–B/MWCNTs, (e) 13.50wt.% Fe–B/MWCNTs, (f) 20.65wt.% Fe–B/MWCNTs and (g) Fe–B at low magnifications.

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(a)

(b)

(c)

(d)

(e)

Fig.S3 Particle size distribution histograms of (a) 3.33wt.% Fe–B/MWCNTs, (b) 6.74wt.%

Fe–B/MWCNTs,

(c)

9.86wt.%

Fe–B/MWCNTs,

Fe–B/MWCNTs and (f) 20.65wt.% Fe–B/MWCNTs.

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(d)

13.50wt.%


Fig.S4 The typical TEM image of Fe–B/MWCNTs with a few large particles in the TEM studies.

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Fig.S5 Small angle XRD patterns of (a) MWCNTs, (b) 3.33wt.% Fe–B/MWCNTs, (c) 6.74wt.%

Fe–B/MWCNTs,

(d)

9.86wt.%

Fe–B/MWCNTs,

Fe–B/MWCNTs (f) 20.65wt.% Fe–B/MWCNTs and (g) Fe–B.

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(e)

13.50wt.%


Fig.S6

Overall XPS spectra of (a) MWCNTs, (b) 3.33wt.% Fe–B/MWCNTs, (c)

6.74wt.%

Fe–B/MWCNTs,

(d)

9.86wt.%

Fe–B/MWCNTs,

(e)

13.50wt.%

Fe–B/MWCNTs, (f) 20.65wt.% Fe–B/MWCNTs and (g) Fe–B.

Fig.S7 The typical Fe2p3/2XPS spectra of Fe/MWCNTs and Fe/C prepared by reduction with N2H4.

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Fig.S8 H2/N2 ratio of the gas released from 200mL aqueous N2H4 solution in the presence of 0.5g (a) 3.33wt.% Fe–B/MWCNTs, (b) 6.74wt.% Fe–B/MWCNTs, (c) 9.86wt.%

Fe–B/MWCNTs,

(d)

13.50wt.%

Fe–B/MWCNTs and (f) Fe–B .

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Fe–B/MWCNTs,

(e)

20.65wt.%


Fig.S9 Hydrogen released from 200mL aqueous N2H4 solution in the presence of 0.5g (a) MWCNTs, (b) 3.33wt.% Fe–B/MWCNTs, (c) 6.74wt.% Fe–B/MWCNTs, (d) 9.86wt.% Fe–B/MWCNTs, (e) 13.50wt.% Fe–B/MWCNTs, (f) 20.65wt.% Fe–B/MWCNTs and (g) Fe–B.

Fig.S10 Typical UV-Vis spectra of hydrous hydrazine (a) before and (b) after the completion of hydrazine decomposition reaction over the Fe-B catalysts.

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Fig.S11 The typical in-situ Fe2p3/2XPS spectra of Fe-B catalysts during the hydrazine decomposition reaction.

Fig.S12 Hydrogen released from 200mL 0.5molL-1 aqueous N2H4 solution with different concentrations (a) 0.01, (b) 0.02, (c) 0.03, (d) 0.05, (e) 0.075, (f) 0.1, (g) 0.2, (h) 0.5, (i) 1, (j) 5, (k) 7.5 and (l) 10.0molL-1in the presence of 0.5g 9.86wt.% Fe–B/MWCNTs.

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Fig.S13 Hydrogen selectivity versus N2H4 concentrations for the decomposition of N2H4 over 9.86wt.% Fe–B/MWCNTs at 293K.

Fig.S14 Solution gravimetric hydrogen densities versus N2H4 concentrations for the decomposition of N2H4 over 9.86wt.% Fe–B/MWCNTs at 293K.

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Fig.S15 CO2-TPD spectra of (a) MWCNTs and (b) KOH-modified MWCNTs.

Fig.S16 (a) XRD pattern and (b) EDAX spectrum of 9.86wt.% Fe–B/MWCNTs after a lifetime test over 30h.

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Fig.S17 (a) Overall XPS spectrum, (b) Fe2p3/2 XPS spectrum and (c) B1s XPS spectrum of 9.86wt.% Fe–B/MWCNTs after a lifetime test over 30h.

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