advances.sciencemag.org/cgi/content/full/3/2/e1601945/DC1

Supplementary Materials for

High performance of a cobalt–nitrogen complex for the reduction and

reductive coupling of nitro compounds into amines and their derivatives

Peng Zhou, Liang Jiang, Fan Wang, Kejian Deng, Kangle Lv, Zehui Zhang

Published 17 February 2017, Sci. Adv. 3, e1601945 (2017)

DOI: 10.1126/sciadv.1601945

This PDF file includes:

fig. S1. Structure of cobalt phthalocyanine.

fig. S2. TGA of the cobalt phthalocyanine/silica composite under a N2 atmosphere.

fig. S3. Solid UV-Vis spectra of the samples after the pyrolysis of the cobalt phthalocyanine/silica composite at different temperatures.

fig. S4. TEM images of the Co/N-C-SiO2-X samples.

fig. S5. Particle size distribution of Co nanoparticles.

fig. S6. Higher-resolution TEM images of the Co/N-C-AT-X samples.

fig. S7. XRD patterns of the samples.

fig. S8. Higher-resolution Co 2p XPS spectra.

fig. S9. Higher-resolution C 1s XPS spectra.

fig. S10. Higher-resolution N 1s XPS spectra.

fig. S11. Reaction pathways of the reduction of nitrobenzene.

fig. S12. Time course of the molar percentage of each compound during the hydrogenation of the nitrobenzene process.

fig. S13. GC analysis of the hydrogenation of nitrobenzene over the Co/Nx-C-800-AT catalyst at low reaction temperatures.

fig. S14. Molar percentage of the samples at three different temperatures.

fig. S15. Plot of ln(Ct/C0) versus time for the reduction of nitrobenzene over the Co–Nx/C-800-AT catalyst at different temperatures.

fig. S16. Tandem reaction of nitrobenzene with primary amines to produce imines.

fig. S17. Reductive N-formylation of nitrobenzene to N-phenylformamide by formic acid.

fig. S18. Synthesis of benzimidazole with o-dinitrobenzene and formic acid.

table S1. The content of Co and N in the as-prepared catalysts.

table S2. Recycling results for the Co–Nx/C-800-AT catalyst.

General

All of the solvents were purchased from Sinopharm Chemical Reagent Co., Ltd. (Shanghai,

China). All of the chemicals were purchased from Aladdin Chemicals Co. Ltd. (Beijing, China).

LUDOX® HS-40 colloidal silica (40 wt % in H2O) was purchased from Sigma-Aldrich

(St Louis, USA). Cobalt phthalocyanine (Fig. 1) was purchased from Tuopu Chemicals Co. Ltd.

(Wuhan, China).

fig. S1. Structure of cobalt phthalocyanine.

Catalyst characterization

Transmission electron microscope (TEM) was performed on an FEI Tecnai G2-20 instrument.

X-ray powder diffraction (XRD) measurements were conducted on a Bruker advanced D8 powder

diffractometer (Cu Kα), operating with 2θ range of 10–80° at a scanning rate of 0.016 °/s. X-ray

photoelectron spectroscopy (XPS) experiments were carried out on a Thermo VG scientific

ESCA MultiLab-2000 spectrometer with a monochromatized Al Kα source (1486.6 eV) at

constant analyzer pass energy of 25 eV. The cobalt content was determined by inductively

coupled plasma atomic emission spectrometer (ICP-AES) on an IRIS Intrepid II XSP instrument

(Thermo Electron Corporation). Raman spectra were measured on a confocal laser micro-Raman

spectrometer (Thermo Fischer DXR) equipped with a diode laser of excitation of 532 nm (laser

serial number: AJC1200566). Spectra were obtained at a laser output power of 1 mW (532 nm),

and a 0.2 s acquisition time with 900 lines/mm grating (Grating serial number: AJG1200531).

UV–Visible absorption spectra were recorded on a Shimadzu UV-2550 spectrophotometer

(Kyoto, Japan). Thermogravimetric (TG) analysis was performed with a thermogravimetric

analyzer (NETZSCH TG209) at a heating rate of 10 K·min-1 and a nitrogen flow of 20 mL·min-1.

Nitrogen physisorption measurements were conducted at 77 K on a quantachrome Autosorb-1-

C-MS instrument.

http://www.google.com.hk/search?hl=zh-CN&newwindow=1&safe=strict&client=aff-9991&hs=DDJ&tbo=d&channel=link&source=hp&site=webhp&spell=1&q=powder+diffractometer&sa=X&ei=sJ26UPGBMoiPiAfk4IDgBA&ved=0CC4QvwUoAAhttp://www.google.com.hk/search?hl=zh-CN&newwindow=1&safe=strict&client=aff-9991&hs=DDJ&tbo=d&channel=link&source=hp&site=webhp&spell=1&q=powder+diffractometer&sa=X&ei=sJ26UPGBMoiPiAfk4IDgBA&ved=0CC4QvwUoAA

Analytic methods

Analysis of the products was performed by a gas chromatography (GC) on a agilent 7890A

instrument with a crosslinked capillary HP-5 column (30 m×0.32 mm×0.4 mm) equipped with a

flame ionization detector. Operating conditions were as follows: The flow rate of the N2 carrier

gas was 40 mL·min-1, the injection port temperature was 300 °C. The GC oven temperature

program was as follows: 50 °C ramp 10 °C/min to 280 °C and the detector temperature was

300 °C. The peaks were identified by comparison of the retention time of the unknown

compounds with those of standard compounds and quantified based on the internal standard

method using 4-chlorotoluene as the internal standard.

100 200 300 400 500 600 700 800 90050

60

70

80

90

100

8.3%

5.4%

10.4%

Wei

gh

t (%

)

Temperature ( o

C)

fig. S2. TGA of the cobalt phthalocyanine/silica composite under a N2 atmosphere.

cobalt phthalocyanine/silica composite

Co/N-C-SiO2-200

Co/N-C-SiO2-400

Co/N-C-SiO2-600

Co/N-C-SiO2-800

300 400 500 600 700 800

Ab

sorb

an

ce (

a.u

.)

Wavelength (nm)

fig. S3. Solid UV-Vis spectra of the samples after the pyrolysis of the cobalt

phthalocyanine/silica composite at different temperatures.

fig. S4. TEM images of the Co/N-C-SiO2-X samples. (a) Co/N-C-SiO2-400; (b) Co/N-C-SiO2-

600; (c) Co/N-C-SiO2-800; (d) Co/N-C-SiO2-900.

5-10 10-15 15-20 20-250

10

20

30

40

Perc

en

tag

e (

%)

Particle size (nm)

(a)

10-15 15-20 20-25 25-30 30-350

5

10

15

20

25

30

35

40(b)

Pe

rce

nta

ge

(%

)

Particle size (nm)

fig. S5. Particle size distribution of Co nanoparticles. (a) Co/N-C-SiO2-800; (b) Co/N-C-

SiO2-900.

fig. S6. Higher-resolution TEM images of the Co/N-C-AT-X samples. (a) Co-Nx/C-800-AT;

(b) Co-Nx/C-900-AT.

10 20 30 40 50 60 70 80

-800

-400

0

400

800

1200

1600

(d)

(c)

(b)

2

Inte

nsit

y (

a.u

.)

Metallic Co

(a)

fig. S7. XRD patterns of the samples. (a) Co/N-C-SiO2-900; (b) Co/N-C-SiO2-800; (c) Co/N-C-

SiO2-600; (d) Co/N-C-SiO2-400.

800 795 790 785 780 77536000

38000

40000

42000

44000

Co 2p1/2

Inte

nsit

y (

a.u

.)

Binding energy (eV)

781.2

Co 2p3/2

(a)

800 795 790 785 780 77536000

38000

40000

42000

44000

Co 2p1/2

(b)

Binding energy (eV)

781.2

Co 2p3/2

Inte

nsit

y (

a.u

.)

fig. S8. Higher-resolution Co 2p XPS spectra. (a) Co-Nx/C-800-AT; (b) Co-Nx/C-900-AT.

296 294 292 290 288 286 284 282 2800

10000

20000

30000

40000

50000

60000

C-C/C=C (284.5 eV)

C-N (285.1 eV)

C-O (286.0 eV)

C-N=C (288.3 eV)

Inte

ns

ity

(a

.u.)

Binding Energy (eV)

C 1s

(a)

292 290 288 286 284 282 2800

10000

20000

30000

40000

50000

60000

70000

80000C 1s

Inte

nsit

y (

a.u

.)

Binding Energy (eV)

C-C/C=C (284.5 eV)

C-N (285.1 eV)

C-O (286.0 eV)

C-N=C (288.3 eV)

(b)

fig. S9. Higher-resolution C 1s XPS spectra. (a) Co/N-C-800-BT; (b) Co-Nx/C-800-AT.

408 406 404 402 400 398 39616000

17000

18000

19000

20000

21000

22000

23000

Binding Energy (eV)

(a)

Inte

nsit

y (

a.u

.)

pyridinic N (398.4 eV)

pyrolic N (400.3 eV)

graphene N (401.0 eV)

N 1s

408 406 404 402 400 398 396

17000

18000

19000

20000

21000

22000

23000

24000

Binding Energy (eV)

Inte

nsit

y (

a.u

.)

(b)

N 1s

pyridinic N (398.4 eV)

pyrolic N (400.3 eV)

graphene (401.0 eV)

N

fig. S10. Higher-resolution N 1s XPS spectra. (a) Co/N-C-800-BT; (b) Co-Nx/C-800-AT.

fig. S11. Reaction pathways of the reduction of nitrobenzene.

0.0 0.5 1.0 1.5

0

20

40

60

80

100 Nitrobenzene

Aniline

Mo

lar

per

cen

tag

e (%

)

Time (h)

fig. S12. Time course of the molar percentage of each compound during the hydrogenation

of the nitrobenzene process. Reaction conditions: Nitrobenzene (1 mmol), Co-Nx/C-800-AT

catalyst (40 mg), H2O (15 mL), H2 pressure (3.5 bar), 110 °C.

4.0 4.5 5.0 5.5 6.0 6.5

Phenylhydroxylamine

40 C

30 C

60 C

Nitrobenzene

Aniline

4-Chlorotoluene

Retention time (min)

fig. S13. GC analysis of the hydrogenation of nitrobenzene over the Co/Nx-C-800-AT catalyst

at low reaction temperatures. Reaction conditions: Nitrobenzene (0.5 mmol), 4-Chlorotoluene

(0.5mmol) as internal standard, Co-Nx/C-800-AT catalyst (20 mg), acetonitrile (15 mL), H2

pressure (50 bar), 1 h.

30 40 50 600

20

40

60

80

Per

cen

tage

(%)

Temperature ( oC)

Phenylhydroxylamine

Nitrobenzene

Aniline

fig. S14. Molar percentage of the samples at three different temperatures. Reaction

conditions: Nitrobenzene (0.5 mmol), 4-chlorotoluene (0.5mmol) as internal standard, Co-Nx/

C-800-AT catalyst (20 mg), acetonitrile (15 mL), H2 pressure (50 bar), 1 h.

0 20 40 60 80 100

-1.2

-1.0

-0.8

-0.6

-0.4

-0.2

0.0

0.00310 0.00315 0.00320 0.00325 0.00330

-5.6

-5.4

-5.2

-5.0

-4.8

-4.6

-4.4

-4.2

-4.0

-3.8

ln(k

)

1/T

Time (min)

ln(C

t/C

0)

T= 40 C, k = 0.0059 min-1

T = 50 C, k = 0.021 min-1

T = 30 C, k = 0.0040 min-1

Ea = 44.81 kJmol-1

fig. S15. Plot of ln(Ct/C0) versus time for the reduction of nitrobenzene over the Co–Nx/

C-800-AT catalyst at different temperatures. The inset shows the corresponding Arrhenius plot.

Reaction conditions: nitrobenzene (1 mmol), Co-Nx/C-800-AT catalyst (40 mg), H2O (15 mL),

H2 pressure (50 bar).

fig. S16. Tandem reaction of nitrobenzene with primary amines to produce imines.

fig. S17. Reductive N-formylation of nitrobenzene to N-phenylformamide by formic acid.

fig. S18. Synthesis of benzimidazole with o-dinitrobenzene and formic acid.

table S1. The content of Co and N in the as-prepared catalysts.

Catalysts Co wt% by ICP N at % by XPS

Co-Nx/C-600-AT 0.36 14.34

Co-Nx/C-800-AT 0.25 8.16

Co-Nx/C-900-AT 0.18 5.38

Co/N-C-800-BT 12.3 6.28

table S2. Recycling results for the Co–Nx/C-800-AT catalyst.

Run No. Conversion (%) Selectivity (%)

1 100 >99

2 100 >99

3 100 >99

4 100 >99

5 100 >99

6 100 >99

7 100 >99

8 100 >99

Reaction conditions: Nitrobenzene (1 mmol), Co-Nx/C-800-AT (40 mg), 3.5 bar H2, H2O

(15 mL), 110 °C, 1.5 h.