Supplementary Information. for. Zeolites ZSM-25 and PST-20: Selective Carbon Dioxide Adsorbents at High. Pressures

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1 S1 Supplementary Information for Zeolites ZSM-25 and PST-20: Selective Carbon Dioxide Adsorbents at High Pressures Jung Gi Min, K. Christian Kemp, and Suk Bong Hong* Center for Ordered Nanoporous Materials Synthesis, Division of Environmental Science and Engineering, POSTECH, Pohang 37673, Korea

2 S2 Zeolite Synthesis The reagents employed in this study included NaOH (50%, aqueous solution, Aldrich), KOH (45%, aqueous solution, Aldrich), CsNO 3 (99%, Aldrich), Sr(NO 3 ) 2 (99%, Aldrich), 1,4,7,10,13,16-hexaoxacyclooctadecane (18-crown-6, 99%, Aldrich), tetraethylammonium bromide (TEABr, 98%, Aldrich), tetraethylammonium hydroxide (TEAOH, 35%, Aldrich), tetramethylammonium hydroxide (TMAOH, 25%, Aldrich), aluminum hydroxide (Al(OH) 3 H 2 O, Aldrich), Al powder (99.5%, Aldrich), colloidal silica (Ludox AS-40 or Ludox HS-40, DuPont), and deionized water. Zeolites Rho, ECR-18, ZSM-25, PST-20, and chabazite were synthesized according to the procedures reported in the literature. S1-S5 The compositions of the aluminosilicate gels used in their synthesis are given in Table S1. The final synthesis mixtures were charged into 23 ml Teflon lined autoclaves and heated under rotation (60 rpm) at given temperatures for different times. The solid products were separated by centrifugation (15000 rpm, 10 min). The recovered solids were re-dispersed in deionized water using a sonication bath (100 W, 42 khz) for 60 min and followed by centrifugation, which was repeated three times. Among the as-made zeolites synthesized here, PST-20 was further washed with copious hot water to remove excess Sr 2+ on the external surface of its crystallities. For comparison, zeolite Na-A was obtained from Aldrich. Analytical Methods Powder X-ray diffraction (XRD) patterns were measured on a PANalytical X pert diffractometer (Cu Kα radiation) with an X Celerator detector. For the identification of phases, the samples were analyzed in the 2θ range 5-50 in steps of For the calculation of unit cell parameters, long-step scans were taken in the 2θ range 5-50 with a step size of 0.02 and a count time of 300 s per step. To obtain the long-step scans of dehydrated samples, in addition, the zeolite powder was mounted on a Pt heat strip inside an Edmund Bühler HDK

3 S3 1.4 high-temperature XRD chamber and heated at a rate of 10 K min -1, held at 523 K for 2 h under a dynamic vacuum of 0.1 Torr. After being cooled to 298 K, the powder XRD data were collected in the same manner. Unit cell parameters were obtained by the Fullprof program S6 or the Lebail method S7 using the GSAS suite of programs. S8 Crystal morphology and size were determined using a JEOL JSM-6510 scanning electron microscope (SEM). Elemental analysis for Si, Al, and Na was performed on a Jarrell-Ash Polyscan 61E inductively coupled plasma spectrometer in combination with a PerkinElmer 5000 atomic absorption spectrophotometer. The C, H, and N contents of the solid product samples were analysed by using a Vario EL III elemental organic analyser. 13 C MAS NMR measurements were performed on an Agilent Unity Inova 600 spectrometer at a spinning rate of 22.0 khz. The spectra were recorded at a 13 C frequency of MHz with a π/2 rad pulse length of 2.5 μs, a recycle delay of 13 s, and acquisition of ca pulse transients. The 13 C chemical shifts are referenced relative to TMS. (S1) Chatelain, T.; Patarin, J.; Fousson, E.; Soulard, M.; Guth, J. L.; Schulz, P. Synthesis and Characterization of High-Silica Zeolite RHO Prepared in the Presence of 18-Crown-6 Ether as Organic Template. Microporous Mater. 1995, 4, (S2) Kim, D. J.; Shin, C.-H.; Hong, S. B. Synthesis and Characterization of a Gallosilicate Analog of Zeolite Paulingite. Microporous Mesoporous Mater. 2005, 83, (S3) Hong, S. B.; Paik, W. C.; Lee, W. M.; Kwon, S. P.; Shin, C.-H.; Nam, I.-S.; Ha, B.-H. Synthesis and Characterization of Zeolite ZSM-25. Stud. Surf. Sci. Catal. 2001, 135, 186. (S4) Guo, P.; Shin, J.; Greenaway, A. G.; Min, J. G.; Su, J.; Choi, H. J.; Liu, L.; Cox, P. A.; Hong, S. B.; Wright, P. A.; Zou, X. A Zeolite Family with Expanding Structural Complexity and Embedded Isoreticular Structures. Nature 2015, 524,

4 S4 (S5) Shang, J.; Li, G.; Singh, R.; Gu, Q.; Narin, K. M.; Bastow, T. J.; Medhekar, N.; Doherty, C. M.; Hill, A. J.; Liu, J. Z.; Webley, P. A. Discriminative Separation of Gases by a Molecular Trapdoor Mechanism in Chabazite Zeolites. J. Am. Chem. Soc. 2012, 134, (S6) Rodríguez-Carvajal, J. Recent Advances in Magnetic Structure Determination by Neutron Powder Diffraction. J. Physica B. 1993, 192, (S7) Bail, A. L.; Duroy, H.; Fourquet, J. L. Ab-Initio Structure Determination of LiSbWO 6 by X-Ray Powder Diffraction. Mater. Res. Bull. 1988, 23, (S8) Larson, A. C.; Dreele, R. B. V. General Structure Analysis System (GSAS). Report No. LAUR , Los Alamos National Laboratory, 2004.

5 zeolite gel composition a Table S1. Oxide Compositions of the Aluminosilicate Gels Used in the Synthesis of Zeolites Employed in This Work (K / days) seeding ref. temp./time chabazite 1.0TMA 2 O 4K 2 O 1.0Al 2 O 3 8.0SiO 2 200H 2 O 373/168 no S5 Rho 1.0(18C6) 1.4Na 2 O 0.7Cs 2 O 1.0Al 2 O 3 10SiO 2 140H 2 O 383/96 no S1 ECR TEA 2 O 0.9Na 2 O 0.4K 2 O 1.0Al 2 O 3 9.0SiO 2 140H 2 O 373/122 no S2 ZSM TEA 2 O 1.9Na 2 O 1.0Al 2 O 3 7.2SiO 2 390H 2 O 408/106 no S3 PST TEA 2 O 1.9Na 2 O 0.25SrO 1.0Al 2 O 3 7.2SiO 2 390H 2 O 418/72 yes b S4 a TMA, tetramethylammonium; 18C6, 1,4,7,10,13,16-hexaoxacyclooctadecane; TEA, tetraethylammonium. b A small amount (2 wt % of anhydrous raw materials) of as-made PST- 20 crystals was added as seeds to the synthesis mixture. S5

6 Table S2. Unit Cell Compositions of the Dehydrated Form of Zeolites Employed Here zeolite unit cell composition Si/Al TEA/Al Na-A Na 12 [Al 12 Si 12 O 48 ] Na-chabazite Na 11 [Al 11 Si 25 O 72 ] Na-Rho Na 10 [Al 10 Si 38 O 96 ] Na-ECR-18 Na 145 H 5 [Al 150 Si 522 O 1344 ] NaTEA-ECR-18 (N(C 2 H 5 ) 4 ) 26 Na 140 (OH) 16 [Al 150 Si 522 O 1344 ] Na-ZSM-25 Na 285 [H 40 Al 325 Si 1115 O 2880 ] NaTEA-ZSM-25 (N(C 2 H 5 ) 4 ) 45 Na 285 [Al 325 Si 1115 O 2880 ] Na-PST-20 Na 528 [H 80 Al 608 Si 2002 O 5280 ] NaTEA-PST-20 (N(C 2 H 5 ) 4 ) 79 Na 560 Sr 11 [Al 608 Si 2002 O 5280 ] S6

7 S7 Table S3. Numbers of Different Types of Cages per Unit Cell in the RHO-Gn Members of the RHO Family of Zeolites a RHO-G1 (Rho) N [ ] lta [ ] d8r [ ] pau [ ] t-plg [ ] t-oto [ ] t-gsm [ ] t-phi (N t-oto + N t-gsm + N t-phi ) / N RHO-G RHO-G3 (ECR-18) RHO-G4 (ZSM-25) RHO-G5 (PST-20) a The number of cages was calculated as follows: N lta = 2; N d8r = 6n; N pau = 6(n-1); N t-plg = 8(n-1); N t-oto = 12n(n-1); N t-gsm = 2(n- 1)(n-2)(2n-3); N t-phi = 12(n-1)(n-2).

8 Figure S1. Experimental setup for breakthrough measurements (MFC: mass flow controller, QMS: quadrupole mass spectrometer). S8

9 S9 Figure S2. Powder XRD patterns and SEM images of (a) Na-A, (b) Na-chabazite, (c) Na-Rho, (d) Na-ECR-18, (e) NaTEA-ECR-18, (f) Na-ZSM-25, (g) NaTEA-ZSM-25, (h) Na-PST-20, and (i) NaTEA-PST-20.

10 S10 Figure S3. Low-pressure adsorption isotherms at 298 K of CO 2 (navy), N 2 (pink), and CH 4 (green) on (a) Na-A, (b) Na-CHA, (c) Na-Rho, (d) NaTEA-ECR-18, (e) NaTEA-ZSM-25, and (f) NaTEA-PST-20. Simultaneous fit of all data with the generalized dual-site Langmuir isotherm (solid line).

11 S11 Figure S4. Adsorption isotherms of CO 2 (navy), N 2 (pink), and CH 4 (green) at 0-1 bar (left) and 0-25 bar (right) on (a) ECR-18, (b) ZSM-25, and (c) PST-20 at 298 K. Simultaneous fit of all data with the generalized dual-site Langmuir isotherm (solid line).

12 S12 Figure S5. 13 C MAS NMR spectra of as-made (a) ECR-18, (b) ZSM-25, and (c) PST-20. The 13 C solution NMR spectrum of tetraethylammonium bromide (TEABr) in D 2 O (bottom trace) is also included for comparison.

13 S13 Figure S6. Adsorption isotherms of CO 2 at 298 ( ), 323 ( ), 248 ( ), and 373 ( ) K and 0-1 bar (left) and 0-25 bar (right) on (a) Na-Rho, (b) Na-ECR-18, (c) NaTEA-ECR-18, and (d) Na-ZSM-25. Data fitting was performed using the generalized dual-site Langmuir isotherm (solid line).

14 S14 Figure S6 continued. Adsorption isotherms of CO 2 at 298 ( ), 323 ( ), 248 ( ), and 373 ( ) K and 0-1 bar (left) and 0-25 bar (right) on (e) NaTEA-ZSM-25, (f) Na-PST-20, and (g) NaTEA-PST-20. Data fitting was performed using the generalized dual-site Langmuir isotherm (solid line).

15 Figure S7. Calculated isosteric heats of CO 2 adsorption on Na-A ( ), Na-chabazite ( ), Na- Rho ( ), NaTEA-ECR-18 ( ), Na-ZSM-25 ( ), NaTEA-ZSM-25 ( ), Na-PST-20 ( ), and NaTEA-PST-20 ( ). 15