Coordination effect-regulated CO2 capture with alkali metal onium

Electronic Supplementary Material (ESI) for Green Chemistry This journal is © The Royal Society of Chemistry 2013

Coordination effect-regulated CO2 capture with alkali metal onium salts/crown ether system Zhen-Zhen Yang, De-en Jiang, Xiang Zhu, Chengcheng Tian, Suree Brown, Chi-Linh Do-Thanh, Liang-Nian He* and Sheng Dai*

Table of Contents page 1. General experimental methods

S2

2. Synthesis of alkali metal onium salts

S2

3. Characterization of ProK/18-crown-6/PEG300 and 4-Cl-PhOK/18-crown-6/PEG300 S2 (1H, 13C NMR and FT-IR) before and after CO2 capture 4. Scanning thermogravimetric analysis (TGA) and reusability of the 4-Cl-PhOK/18-crown-6/PEG300 system

S4

5. IR spectra of other absorption systems before and after CO2 capture

S5

S1


1. General experimental methods: Caution Experiments using compressed gase (CO2) are potentially hazardous and must only be carried out by using the appropriate equipment and under rigorous safety precautions. Materials All the reagents used in this work are purchased from Sigma-Aldrich Company and directly used without further purification. CO2 with a purity of 99.99% is commercially available. Experimental methods 1

H and 13C NMR spectra were recorded on a Varian Mercury 300 MHz spectrometer (1H NMR, 300 MHz, 13C NMR, 75 MHz) in CDCl3, the chemical shifts were referenced to the residual solvent. FTIR data were obtained using a Bio-Rad Excalibur FTS-3000 spectrometer. General procedure for absorption and desorption of CO2 In a typical procedure, CO2 capture was carried out in a glass container with an inner diameter of 10 mm. The absorbents were charged into the reactor at room temperature. Then, a needle was used for CO2 bubbling, which was inserted in the bottom of the flask. The absorption reaction was conducted at 25 oC with a CO2 bubbling rate of 80 mL/min. The amount of CO2 absorbed was determined by an analytical balance with an accuracy of ±0.0001 g every five minutes. In a typical desorption of CO2, N2 of atmospheric pressure is bubbled through the absorption system at 50 oC using the same equipment and procedure as CO2 capture. Absorption/desorption is determined by several cycles of repeated experiments.

2. Synthesis of alkali metal onium salts:

The alkali metal onium salts were prepared from the neutralization of various amino acids or phenols with alkali metal hydroxides. For example, in a typical procedure for the synthesis of ProK, equimolar proline was added to an ethanolic solution of KOH. Then, the mixture was stirred at room temperature for 24 h. Subsequently, EtOH was distilled off at 70 oC under vacuum. The obtained solid was washed with ethyl ether three times and dried under vacuum at 80 oC for 24 h.

3. Characterization of ProK/18-crown-6/PEG300 and 4-Cl-PhOK/18-crown-6/PEG300 (1H, 13C NMR and FT-IR) before and after CO2 capture 18-crown-6 1

H NMR (CDCl3, 300 MHz) δ 3.64 (s, 24H);

ProK 1

H NMR (CDCl3, 300 MHz) δ 3.77 (t, 3J = 7.8 Hz, 1H), 3.21-3.29 (m, 1H), 2.96-3.05 (m, 1H), 2.11-2.21 (m, 1H),

1.81-1.99 (m, 3H); ProK/18-crown-6 1

H NMR (CDCl3, 300 MHz) δ 3.61-3.62 (m, 25H), 3.05-3.13 (m, 1H), 2.81-2.89 (m, 1H), 2.03-2.16 (m, 1H),

1.86-1.97 (m, 1H), 1.58-1.72 (m, 2H); ProK/18-crown-6/PEG300

S2


1

H NMR (CDCl3, 300 MHz) δ 3.44-3.58 (m, 78H), 2.94-3.01 (m, 1H), 2.73-2.82 (m, 1H), 1.92-2.04 (m, 1H),

1.79-1.88 (m, 1H), 1.49-1.65 (m, 2H); 13C NMR (CDCl3, 75 MHz) δ 177.7, 77.2, 72.0, 71.9, 69.3-69.7, 61.0, 60.2, 60.1, 46.0, 30.4, 25.1. ProK/18-crown-6/PEG300 + CO2 1

H NMR (CDCl3, 300 MHz) δ 3.98 (s, 1H), 3.56-3.70 (m, 82H), 3.19-3.29 (m, 2H), 2.25 (s, 1H), 1.97-2.09 (m,

1H), 1.70-1.79 (m, 2H); 13C NMR (CDCl3, 75 MHz) δ 175.9, 157.7, 77.2, 72.3, 72.1, 69.5-70.0, 60.8, 60.5, 46.4, 28.9, 24.1. 4-Cl-PhOK 1

H NMR (CDCl3, 300 MHz) δ 7.11 (s, 1H), 7.08 (s, 1H), 6.71 (s, 1H), 6.68 (s, 1H);

4-Cl-PhOK/18-crown-6 1

H NMR (CDCl3, 300 MHz) δ 6.86-6.90 (m, 2H), 6.53-6.57 (m, 2H), 3.60 (s, 84H);

4-Cl-PhOK/18-crwon-6/PEG300 1

H NMR (CDCl3, 300 MHz) δ 6.99 (s, 1H), 6.96 (s, 1H), 6.76 (s, 1H), 6.73 (s, 1H), 3.56-3.70 (m, 140H); 13C

NMR (CDCl3, 75 MHz) δ 165.1, 129.2, 128.0, 119.0, 115.8, 77.2, 72.3, 72.2, 72.18, 69.5, 69.9, 60.4-60.6. 4-Cl-PhOK/18-crown-6/PEG300+CO2 1

H NMR (CDCl3, 300 MHz) δ 6.95-6.99 (m, 2H), 6.73-6.76 (m, 2H), 3.55-3.70 (m, 94H); 13C NMR (CDCl3, 75

MHz) δ 158.7, 157.4, 128.0, 120.3, 117.2, 77.2, 71.9, 69.4-69.8, 60.5. 1

1

O O

4

O

O

O

O K 2 3

O

5

O

Cl

O

O

O

O

4

K O

O

1

O O

5

2 3

O

O 6 O O

4

O

5

K O

Cl

O

3

Cl

1

(a)

18‐crown‐6

3

4‐Cl‐PhOK

2

1 3 3

2 2

4‐Cl‐PhOK/18‐crown‐6 4‐Cl‐PhOK/18‐crown‐6/PEG300 + CO2

S3

2


(b)

3

2

4‐Cl‐PhOK/18‐crown‐6/PEG300 4 4‐Cl‐PhOK/18‐crown‐6/PEG300 + CO2 3 6 4

2 5

4‐ClPhOK/18‐crown‐6/PEG300 4‐ClPhOK/18‐crown‐6/PEG300+CO2 0.2

(c) 0.8

1647 cm‐1

Absorbance

0.7

0.15

0.6

0.1

0.5

0.05

0.4

0 1500

0.3

1600

1700

1800

0.2 0.1 0 600

1600 2600 Wave number/cm‐1

3600

1

Figure S1. (a) H NMR spectra (CDCl3, 300 MHz) of 18-crown-6, 4-Cl-PhOK, 4-Cl-PhOK/18-crown-6 and 4-Cl-PhOK 13 /18-crown-6/PEG300+CO2 (from top to bottom); (b) C NMR spectra (CDCl3, 75 MHz) of 4-Cl-PhOK /18-crown-6/PEG300 before (top) and after (bottom) CO2 absorption. (c) FT-IR spectrum of 4-Cl-PhOK /18-crown-6/PEG300 before (black line) and after (blue line) CO2 absorption.

4. Scanning thermogravimetric analysis (TGA) and reusability of the 4-Cl-PhOK/18-crown-6/PEG300 system

S4


4‐Cl‐PhOK/18‐crown‐ 6/PEG300+CO2 18‐crown‐6

Weight/%

(a) 100 90 80 70 60 50 40 30 20 10 0

PEG300

0

(b)

100

200 300 Temperature/oC

400

500

1

0.9

CO2 capacity

0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0 0

50

100 Time/min

150

200

Figure S2. (a) Scanning thermogravimetric analysis (TGA) results for 4-Cl-PhOK /18-crown-6/PEG300+CO2 with a 10 -1 o o C min temperature ramping rate to 500 C. (b) Six consecutive cycles of CO2 absorption (♦ 15 min, 25 C, CO2) and o release (◊ 20 min, 80 C, N2) by 4-Cl-PhOK/18-crown-6/PEG300 system, data were obtained every 5 min. o

5. IR spectra of other absorption systems before and after CO2 capture

S5


0.8

PhOK/18‐crown‐6/PEG300 PhOK/18‐crown‐6/PEG300+CO2

0.7

0.2

0.6

1649 cm‐1

Absorbance

0.15

0.5

0.1

0.4

0.05

0.3

0 1500

0.2

1550

1600

1650

0.1 0 600


3600

0.6

PhONa/15‐crown‐5/PEG300

0.5

PhONa/15‐crown‐5/PEG300+CO2 0.2 1641 cm‐1 0.15

Absorbance

0.4

0.1 0.05

0.3

0 1500 1600 1700 1800

0.2 0.1 0 700


S6

3700

1700


0.6

PhOLi/12‐crown‐4/PEG300 PhOLi/12‐crown‐4/PEG300+CO2 0.2

0.5

1603 cm‐1

Absorbance

0.15 0.4 0.1 0.05

0.3

0 1500 1550 1600 1650 1700

0.2 0.1 0 600


3600

ProNa/15‐crown‐5/PEG300 0.6

ProNa/15‐crown‐5/PEG300+CO2 0.2 ‐1

1589 cm

Absorbance

0.5

1622 cm‐1

0.15 0.1

0.4

0.05 0.3

0 1500

0.2

1600

1700

0.1 0 600


S7

3600

1800


0.9

ValK/18‐crown‐6/PEG300 ValK/18‐crown‐6/PEG300+CO2

0.8

Absorbance

0.7 0.6 0.5 0.4 0.3

1659 cm‐1

0.2 0.1 0 600

1100

1600 2100 2600 3100 Wave number/cm‐1

0.8

3600

MetK/18‐crown‐6/PEG300

0.7

MetK/18‐crown‐6/PEG300+CO2

Absorbance

0.6 0.5 0.4 0.3 0.2

1661 cm‐1

0.1 0 600

1100

1600

2100

2600

3100

3600

Wave number/cm‐1 0.9

GlyK/18‐crown‐6/PEG300 GlyK/18‐crown‐6/PEG300+CO2

0.8 0.7

Absorbance

0.6 0.5 0.4 0.3

1658 cm‐1

0.2 0.1 0 600

1100

1600 2100 2600 Wave number/cm‐1

S8

3100

3600


0.8

ThrK/18‐crown‐6/PEG300

0.7

ThrK/18‐crown‐6/PEG300+CO2

Absorbance

0.6 0.5 0.4 0.3

1659 cm‐1

0.2 0.1 0 600

1100

1600 2100 2600 Wave number/cm‐1

0.9

3600

AlaK/18‐crown‐6/PEG300 AlaK/18‐crown‐6/PEG300+CO2

0.8

1597 cm‐1 1620 cm‐1

0.7

Absorbance

3100

0.2

0.6 0.1

0.5 0.4

0 1500 1600 1700 1800

0.3 0.2 0.1 0 600


3600

0.8

LeuK/18‐crown‐6/PEG300

0.7

LeuK/18‐crown‐6/PEG300+CO2

Absorbance

0.6 0.5 0.4 0.3

1661 cm‐1

0.2 0.1 0 600

1100

1600

2100

2600

Wave number/cm‐1 S9

3100

3600


0.8

SerK/18‐crown‐6/PEG300

0.7

SerK/18‐crown‐6/PEG300+CO2

Absorbance

0.6 0.5 0.4 0.3 0.2

1661 cm‐1

0.1 0 600

1100

1600 2100 2600 3100 Wave number/cm‐1

S10

3600