[Supporting Information] Fabrication of COF-MOF Composite Membranes and Their Highly Selective Separation of H 2 /CO 2 Jingru Fu, a Saikat Das, a Guolong Xing, a Teng Ben, a * Valentin Valtchev a,b and Shilun Qiu a [*] a Department of Chemistry, Jilin University, Changchun, China. Fax: (+86)431-85168298 E-mail: tben@jlu.edu.cn b Normandie Univ, ENSICAEN, UNICAEN, CNRS, Laboratoire Catalyse et Spectrochimie, 14000 Caen, France S1
Table of Contents 1. Instruments S3 2. Materials S7 3. Chemical reactions involved (Schemes S1, S2 and S3) S8 4. Fourier transform infrared spectroscopy (FTIR) S10 5. X-ray diffraction (XRD) S13 6. Thermogravimetric analysis (TGA) S15 7. Low pressure N 2 sorption measurements S16 8. Low pressure H 2, CO 2 and CH 4 sorption measurements S19 9. Gas separation measurements S22 10. In-situ energy-dispersive X-ray spectroscopy (EDS) results S29 S2
1. Instruments 1-1. Fourier transform infrared spectroscopy (FTIR) The FTIR spectra (KBr) were obtained using a SHIMADZU IRAffinity-1 Fourier transform infrared spectrophotometer. 1-2. X-ray diffraction (PXRD) The XRD measurements were carried out using SHIMADZU XRD-6000 X-ray diffractometer with Cu-Kα radiation, 40 kv, 30 ma and scanning rate of 0.3 o min -1 (2θ). 1-3. Thermogravimetric analysis (TGA) The samples (COF-300 powder, Zn 2 (bdc) 2 (dabco) powder and ZIF-8 powder) were put in an alumina pan followed by thermogravimetric analysis (TGA) with SHIMADZU DTG-60 thermal analyzer at a heating rate of 10 o C min -1 to 900 o C in a dried air atmosphere. The air flow rate was 30 ml min -1. 1-4.Scanning electron microscopy (SEM) and elemental mapping analysis Scanning electron microscopy (SEM) and elemental mapping analysis were carried out with JEOS JSM 6700 scanning electron microscope. 1-5. Low pressure N 2 sorption measurements The low pressure N 2 sorption measurements were carried out with Micro Meritics Tristar II 3020 surface area and pore size analyzer. Firstly, the solvents (CH 3 OH, DMF etc.) in the pore were cleared followed by activation of the samples in dynamic vacuum at a certain S3
temperature overnight. After this, the samples were degassed at a certain temperature for 12 h. A sample (80 mg) and a nitrogen (99.999% purity) gas source were employed in the nitrogen sorption measurements at 77 K. 1-6. Low pressure H 2, CO 2 and CH 4 sorption measurements Firstly, samples (COF-300 powder, Zn 2 (bdc) 2 (dabco) powder and ZIF-8 powder) of known weight (80 mg) were placed in the sample tubes (weighed beforehand) that were then sealed to avoid the samples from coming in contact with air and moisture. After this, the samples were heated in the sample tubes in vacuum (at a pressure of 100 mtorr or less) and were then kept at a certain temperature and pressure less than 50 mtorr for a minimum of 10 h. The lowpressure H 2, CH 4, and CO 2 sorption measurements were carried out with Micromeritics Tristar II 3020 surface area and pore size analyzer. Post evacuation, the weight of the tubes holding the degassed samples was measured in pursuance of getting to know the mass of the evacuated samples. Ultra-high-purity grade H 2,CO 2 (99.999 % purity), and CH 4 (99.99 % purity) gases were employed for the sorption measurements. The free space was measured with He (99.999 % purity). The H 2 isotherms at 77 K were measured in a liquid nitrogen bath and H 2 isotherms at 87 K in a liquid argon bath. The CO 2 isotherms at 273 K were measured in an ice-water bath and CO 2 isotherms at 298 K in water bath. The CH 4 isotherms at 273 K were measured in an ice-water bath and CH 4 isotherms at 298 K in water bath. S4
1-7. Gas separation measurements In regard to the single gas measurements, He was used as the sweep gas and H 2, CO 2 and CH 4 were used as the feed gases. The flow rate of sweep gas was 150 ml min -1 and that of the feed gases were 50 ml min -1. The pressure at both sides of the membrane was maintained at 1 bar and the measurements were taken at room temperature. Concerning the mixed gas measurements, the feed flow rate for each gas in the 1:1 binary mixture was 50 ml min -1. The flow rate of the sweep gas (He) was 150 ml min -1. The pressure at both sides of the membrane was maintained at 1 bar and the measurements were taken at room temperature. α H /CO 2 2 y x H H 2 2 /y /x CO CO 2 2 p p H 2 CO 2 (S1) where H 2 / CO 2 is the separation factor of mixture H 2 /CO 2, x is the molar fraction in the retentate, y is the mole fraction in the permeate, p is the permeance. The permeance measurements were carried out in the 7890A Gas chromatograph. The permeance values ( p ) were converted to corresponding permeability values ( P ) using the formula: p t P (S2) 16 2 3.347 10 mol m /( m s Pa) where p is the permeance (in mol m -2 s -1 Pa -1 ), P is the permeability and t is the thickness (in m ) of the membrane. 1 Barrer = 3.347 10-16 mol m -1 s -1 Pa -1. S5
Figure S1. Schematic illustration of gas separation set-up. (Legends used: MFC: Mass flow controller; GC: Gas chromatograph). 1-8. Transmission electron microscopy (TEM) and energy-dispersive X-ray spectroscopy (EDS) The TEM and EDS measurements were accomplished with JEOL JEM-2100F transmission electron microscope operated at an accelerating voltage of 200 kv. S6
2.Materials Terephthalaldehyde was purchased from Tokyo Chemical industry Co. Ltd.; Isopentyl nitrite (90%), Hypophoaphoeous acid (50%), Aniline (99.0%), Raney-Nickel (50 µm), Triphenylmethanol (99%), Triethylenediamine (98%), Sodium formate (99.5%) and ZnCl 2 (98%) were purchased from Aladdin; Polyaniline (PANI) (Mw = 1.5 x 10 4 ), H 2 BDC (98%), Zn(NO 3 ) 2 6H 2 O (98%) and 2-methylimidazole (99%) were purchased from Aldrich; DMF (99.5%), CH 3 OH (99.5%), 1,4-Dioxane (99.5%), CH 3 COOH (99.5%), N 2 H 4 H 2 O (80%), THF (99.5%), HCl (35%), H 2 SO 4 (98%) and C 2 H 5 OH (99.7%) were purchased from West Long Chemical industry. Nitric acid fuming was purchased from Gang Zhou Chemistry industry. All the glass instruments were purchased from Synthware Glass. SiO 2 disks were purchased from Wanxianghuabo. Emery paper (500 mesh and 1200 mesh) was purchased from Shanghai New Five Kyrgyzstant Abrasives Co. Ltd. Teflon reactors were purchased from Jinan Henghua Sci. S7
3. Chemical Reactions involved Scheme S1. Chemical reactions involved during fabrication of COF membrane CHO H N + CHO CH N OH n CHO n NH 2 NH 2 CHO H 2 N NH 2 H 2 N NH 2 + CH N OH N CH NH 2 n CH N OH n S8
Scheme S2. Chemical reactions involved during fabrication of [COF-300]- [Zn 2 (bdc) 2 (dabco)] composite membrane COOH O O R 1 NH 2 HO O H N H R 1 COOH Zn 2+ + R 2 NH 2 R 2 NH 2 Zn 2+ N 3+ COOH 2+ 2 R 2 NH 2 Zn + + 2 COOH N N R 2 R 2 H N 2 N Zn H 2 N Zn N O O O OH + H + N Scheme S3. Chemical reactions involved during fabrication of [COF-300]-[ZIF-8] composite membrane Zn 2+ + R NH 2 R NH 2 Zn 2+ HN N H HN N Zn N H R 2 + S9
4. Fourier transform infrared spectroscopy (FTIR) Figure S2. FTIR spectra (from 2000 cm -1 to 500 cm -1 ) of terephthaldehyde (red), PANI (blue), and the product obtained from PANI and terephthaldehyde mixture in anhydrous dioxane and 3M aqueous acetic acid water mixture solvent in teflon reactor at 100 o C for 3 days (black). C=N stretching: 1640 cm -1. S10
Figure S3. FTIR spectra ( from 800 cm -1 to 400 cm -1 ) of COF-300 powder (green) and the product obtained with 15 mg COF-300, 272 mg ZnCl 2 and 20 ml CH 3 OH in the teflon reactor at 120 o C for 4 hours (red). Zn-N stretching: 421 cm -1. S11
Figure S4. FTIR spectra (from 4000 cm -1 to 400 cm -1 ) of PANI (black) and the product obtained by the mixture of PANI and ZnCl 2 and CH 3 OH in the teflon reactor at 120 o C for 4 hours (red). Figure S5. FTIR spectra (from 800 cm -1 to 400 cm -1 ) of PANI (black) and the product obtained by the mixture of PANI and ZnCl 2 and CH 3 OH in the teflon ractor at 120 o C for 4 hours (red). S12
5. X-ray diffraction (XRD) Figure S6. XRD pattern of degassed COF-300 powder. S13
Figure S7. XRD patterns of: (a) COF-300 powder, (b) COF-300 membrane, (c) Zn 2 (bdc) 2 (dabco) powder, (d) Zn 2 (bdc) 2 (dabco) membrane, (e) [COF-300]-[Zn 2 (bdc) 2 (dabco)] composite membrane, (f) ZIF-8 powder, (g) ZIF-8 membrane, (h) [COF-300]-[ZIF-8] composite membrane and (i) SiO 2 support. S14
6. Thermogravimetric analysis (TGA) Figure S8. TGA plot of degassed COF-300 powder (a), Zn 2 (bdc) 2 (dabco) powder (b), and ZIF-8 powder (c) in dry air at a rate of 10 o C min -1. S15
7. Low pressure N 2 sorption measurements Figure S9. N 2 sorption isotherms of degassed COF-300 powder (solid symbols: adsorption; open symbols: desorption). The inset illustrates the pore size distribution for COF-300 derived from N 2 adsorption calculated by Density Functional Theory (DFT) method. The surface area is 2286.6 m 2 g -1 and the pore size 2.00 nm. S16
Figure S10. N 2 sorption isotherms of degassed Zn 2 (bdc) 2 (dabco) powder (solid symbols: adsorption; open symbols: desorption). The inset illustrates the pore size distribution for Zn 2 (bdc) 2 (dabco) derived from N 2 adsorption calculated by Density Functional Theory (DFT) method. The surface area is 1274.3 m 2 g -1 and the pore size is 0.85 nm. S17
Figure S11. N 2 sorption isotherms of degassed ZIF-8 powder (solid symbols: adsorption; open symbols: desorption). The inset illustrates the pore size distribution for ZIF-8 derived from N 2 adsorption calculated by Density Functional Theory (DFT) method. The surface area is 1869.5 m 2 g -1 and the pore size is 1.18 nm. S18
8. Low pressure H 2, CO 2 and CH 4 sorption measurements 8-1. Low pressure gas sorption measurements of degassed COF-300 powder Figure S12. (A,C,E) H 2, CO 2 and CH 4 sorption isotherms (solid symbols: adsorption, open symbols: desorption) and (B,D,F) isoteric enthalpy Qst of H 2, CO 2 and CH 4 adsorption respectively for degassed COF-300 powder. S19
8-2. Low pressure gas sorption measurements of degassed Zn 2 (bdc) 2 (dabco) powder Figure S13. (A,C,E) H 2, CO 2 and CH 4 sorption isotherms (solid symbols: adsorption, open symbols: desorption) and (B,D,F) isoteric enthalpy Qst of H 2, CO 2 and CH 4 adsorption respectively for degassed Zn 2 (bdc) 2 (dabco) powder. S20
8-3. Low pressure gas sorption measurements of degassed ZIF-8 powder Figure S14. (A,C,E) H 2, CO 2 and CH 4 sorption isotherms (solid symbols: adsorption, open symbols: desorption) and (B,D,F) isoteric enthalpy Qst of H 2, CO 2 and CH 4 adsorption respectively for degassed ZIF-8 powder. S21
9. Gas separation measurements Table S1. H 2 /CO 2 separation performance for the COF-300 membrane at room temperature and 1 bar with 1:1 binary mixture of H 2 and CO 2. Figure S15. Gas permeability and H 2 /CO 2 selectivity of COF-300 membrane as function of the operating time at room temperature and 1 bar with 1:1 binary mixture of H 2 and CO 2. S22
Table S2. H 2 /CO 2 separation performance for the Zn 2 (bdc) 2 (dabco) membrane at room temperature and 1 bar with 1:1 binary mixture of H 2 and CO 2. Figure S16. Gas permeability and H 2 /CO 2 selectivity of Zn 2 (bdc) 2 (dabco) membrane as function of the operating time at room temperature and 1 bar with 1:1 binary mixture of H 2 and CO 2. S23
Table S3. H 2 /CO 2 separation performance for the ZIF-8 membrane at room temperature and 1 bar with 1:1 binary mixture of H 2 and CO 2. Figure S17. Gas permeability and H 2 /CO 2 selectivity of ZIF-8 membrane as function of the operating time at room temperature and 1 bar with 1:1 binary mixture of H 2 and CO 2. S24
Table S4. H 2 /CO 2 separation performance for the [COF-300]-[Zn 2 (bdc) 2 (dabco)] composite membrane at room temperature and 1 bar with 1:1 binary mixture of H 2 and CO 2. Figure S18. Gas permeability and H 2 /CO 2 selectivity of [COF-300]-[Zn 2 (bdc) 2 (dabco)] composite membrane as function of the operating time at room temperature and 1 bar with 1:1 binary mixture of H 2 and CO 2. S25
Table S5. H 2 /CO 2 separation performance for the [COF-300]-[ZIF-8] composite membrane at room temperature and 1 bar with 1:1 binary mixture of H 2 and CO 2. Figure S19. Gas permeability and H 2 /CO 2 selectivity of [COF-300]-[ZIF-8] composite membrane as function of the operating time at room temperature and 1 bar with 1:1 binary mixture of H 2 and CO 2. S26
Table S6. Single and mixed gas permeability and separation factors for the [COF-300]- [Zn 2 (bdc) 2 (dabco)] composite membrane prepared on porous SiO 2 disk at room temperature and 1 bar (in mixed gases permeation, equimolar mixtures have been used). Permeability is calculated as the membrane permeability multiplied by the membrane thickness. 1 Barrer = 3.347 10-16 mol m -1 s -1 Pa -1. ISF: Ideal separation factor, SF: Separation factor S27
Table S7. Single and mixed gas permeability and separation factors for the [COF-300]-[ZIF- 8] composite membrane prepared on porous SiO 2 disk at room temperature and 1bar (in mixed gases permeation, equimolar mixtures have been used). Permeability is calculated as the membrane permeability multiplied by the membrane thickness. 1 Barrer = 3.347 10-16 mol m -1 s -1 Pa -1. ISF: Ideal separation factor, SF: Separation factor S28
10. In-situ energy-dispersive X-ray spectroscopy (EDS) results Figure S20. EDS spectrum of [COF-300]-[Zn 2 (bdc) 2 (dabco)] composite membrane. S29