Storage of Hydrogen, Methane and Carbon Dioxide in Highly Porous Covalent Organic Frameworks for Clean Energy Applications (Supporting Information: 33 pages) Hiroyasu Furukawa and Omar M. Yaghi Center for Reticular Chemistry, Department of Chemistry and Biochemistry University of California-Los Angeles, Los Angeles, CA 90095-1569, USA Corresponding authors email addresses: furukawa@chem.ucla.edu; yaghi@chem.ucla.edu Relationship of pore volumes S-2 Low-pressure nitrogen and argon isotherms for COFs S-3 Low-pressure hydrogen isotherms for COFs S-7 High-pressure hydrogen isotherms for COFs S-11 Low-pressure methane isotherms for COFs S-15 High-pressure methane isotherms for COFs S-17 Low-pressure carbon dioxide isotherms for COFs S-21 High-pressure carbon dioxide isotherms for COFs S-22 Estimated absolute adsorbed amounts with different packing density S-26 Effect of packing density on absolute adsorbed amounts S-29 Buoyancy correction for adsorbed layer S-30 S-1
Relationship of pore volumes Figure S1. Relationship between pore volume estimated by He buoyancy correction and estimated by DR-plot. Ideally, all plots should be on the broken line. The reason for the deviation is probably attributed to the decomposition of crystals. S-2
Low-pressure nitrogen and argon isotherms for COFs Figure S2. N 2 (red) and Ar (blue) isotherms for COF-1 measured at 77 and 87 K, respectively. Filled and open symbols repreent adsorption and desorption branches. Connecting traces are guides for eyes. Figure S3. N 2 (red) and Ar (blue) isotherms for COF-5 taken at 77 and 87 K, respectively. All symbols are the same as in Figure S2. S-3
Figure S4. N 2 (red) and Ar (blue) isotherms for COF-6 measured at 77 and 87 K, respectively. All symbols are the same as in Figure S2. Figure S5. N 2 (red) and Ar (blue) isotherms for COF-8 measured at 77 and 87 K, respectively. All symbols are the same as in Figure S2. S-4
Figure S6. N 2 (red) and Ar (blue) isotherms for COF-10 measured at 77 and 87 K, respectively. All symbols are the same as in Figure S2. Figure S7. N 2 (red) and Ar (blue) isotherms for COF-102 measured at 77 and 87 K, respectively. All symbols are the same as in Figure S2. S-5
Figure S8. N 2 (red) and Ar (blue) isotherms for COF-103 measured at 77 and 87 K, respectively. All symbols are the same as in Figure S2. S-6
Low-pressure hydrogen isotherms for COFs Figure S9. H 2 isotherms for COF-1 measured at 77 (red) and 87 K (blue). Filled and open symbols repreent adsorption and desorption branches. Fitted curves are obtained by the virial-type expansion, which were used for the Q st estimation. Figure S10. H 2 isotherms for COF-5 measured at 77 (red) and 87 K (blue). All symbols are the same as in Figure S9. S-7
Figure S11. H 2 isotherms for COF-6 measured at 77 (red) and 87 K (blue). All symbols are the same as in Figure S9. Figure S12. H 2 isotherms for COF-8 measured at 77 (red) and 87 K (blue). All symbols are the same as in Figure S9. S-8
Figure S13. H 2 isotherms for COF-10 measured at 77 (red) and 87 K (blue). All symbols are the same as in Figure S9. Figure S14. H 2 isotherms for COF-102 measured at 77 (red) and 87 K (blue). All symbols are the same as in Figure S9. S-9
Figure S15. H 2 isotherms for COF-103 measured at 77 (red) and 87 K (blue). All symbols are the same as in Figure S9. Figure S16. H 2 isotherms for BPL arbon measured at 77 (red) and 87 K (blue). All symbols are the same as in Figure S9. S-10
High-pressure hydrogen isotherms for COFs Figure S17. High-pressure H 2 isotherms for COF-1 measured at 77 K. Circles and squares represent surface excess and absolute adsorbed amounts, and filled and open symbols repreent adsorption and desorption branches. Connecting traces are guides for eyes. Figure S18. High-pressure H 2 isotherms for COF-5 measured at 77 K. All symbols are the same as in Figure S17. S-11
Figure S19. High-pressure H 2 isotherms for COF-6 measured at 77 K. All symbols are the same as in Figure S17. Figure S20. High-pressure H 2 isotherms for COF-8 measured at 77 K. All symbols are the same as in Figure S17. S-12
Figure S21. High-pressure H 2 isotherms for COF-10 measured at 77 K. All symbols are the same as in Figure S17. Figure S22. High-pressure H 2 isotherms for COF-102 measured at 77 K. All symbols are the same as in Figure S17. S-13
Figure S23. High-pressure H 2 isotherms for COF-103 measured at 77 K. All symbols are the same as in Figure S17. Figure S24. High-pressure H 2 isotherms for BPL carbon measured at 77 K. All symbols are the same as in Figure S17. S-14
Low-pressure methane isotherms for COFs Figure S25. CH 4 isotherms for COF-10 measured at 273 (red), 283 (green), and 298 K (blue). Filled and open symbols repreent adsorption and desorption branches. Fitted curves are obtained by the virialtype expansion, which were used for the Q st estimation. Figure S26. Coverage dependency of adsorption enthalpy of CH 4 for COF-10. S-15
Figure S27. CH 4 isotherms for COF-102 measured at 273 (red), 283 (green), and 298 K (blue). All symbols are the same as in Figure S25. Figure S28. Coverage dependency of adsorption enthalpy of CH 4 for COF-102. S-16
High-pressure methane isotherms for COFs Figure S29. CH 4 isotherms for COF-1 measured at 273 (blue) and 298 K (red). Circles and squares represent surface excess and absolute adsorbed amounts, and filled and open symbols repreent adsorption and desorption branches. Fitted curves are obtained by the virial-type expansion, which were used for the Q st estimation. Figure S30. CH 4 isotherms for COF-5 measured at 273 (blue) and 298 K (red). All symbols are the same as in Figure S29. S-17
Figure S31. CH 4 isotherms for COF-6 measured at 273 (blue) and 298 K (red). All symbols are the same as in Figure S29. Figure S32. CH 4 isotherms for COF-8 measured at 273 (blue) and 298 K (red). All symbols are the same as in Figure S29. S-18
Figure S33. CH 4 isotherms for COF-10 measured at 273 (blue) and 298 K (red). All symbols are the same as in Figure S29. Figure S34. CH 4 isotherms for COF-102 measured at 273 (blue) and 298 K (red). All symbols are the same as in Figure S29. S-19
Figure S35. CH 4 isotherms for COF-103 measured at 273 (blue) and 298 K (red). All symbols are the same as in Figure S29. Figure S36. CH 4 isotherms for BPL carbon measured at 273 (blue) and 298 K (red). All symbols are the same as in Figure S29. S-20
Low-pressure carbon dioxide isotherms for COFs Figure S37. CO 2 isotherms for COFs measured at 273 K. Red triangles: COF-1, blue triangles: COF-6, red squares: COF-5, blue squares: COF-8, green squares: COF-10, red circles: COF-102, blue circles: COF-103, black circles: BPL carbon. Adsorption data are shown as closed symbols, desorption data as open symbols, and connecting traces are guides for the eye. S-21
High-pressure carbon dioxide isotherms for COFs Figure S38. High-pressure CO 2 isotherms for COF-1 measured at 273 (blue) and 298 K (red). Circles and squares represent surface excess and absolute adsorbed amounts, and filled and open symbols repreent adsorption and desorption branches. Connecting traces are guides for eyes. Figure S39. High-pressure CO 2 isotherms for COF-5 measured at 273 (blue) and 298 K (red). All symbols are the same as in Figure S38. S-22
Figure S40. High-pressure CO 2 isotherms for COF-6 measured at 273 (blue) and 298 K (red). All symbols are the same as in Figure S38. Figure S41. High-pressure CO 2 isotherms for COF-8 measured at 273 (blue) and 298 K (red). All symbols are the same as in Figure S38. S-23
Figure S42. High-pressure CO 2 isotherms for COF-10 measured at 273 (blue) and 298 K (red). All symbols are the same as in Figure S38. Figure S43. High-pressure CO 2 isotherms for COF-102 measured at 273 (blue) and 298 K (red). All symbols are the same as in Figure S38. S-24
Figure S44. High-pressure CO 2 isotherms for COF-103 measured at 273 (blue) and 298 K (red). All symbols are the same as in Figure S38. Figure S45. High-pressure CO 2 isotherms for BPL carbon measured at 273 (blue) and 298 K (red). All symbols are the same as in Figure S38. S-25
Effect of packing density on absolute adsorbed amounts Figure S46. Estimated absolute adsorbed amounts of H 2 in COF-6 (A), COF-5 (B), and COF-102 (C) at 77 K with different packing density. Red, blue, green, and purple symbols represent adsorption branche of the isotherms with the packing density of 1.0, 0.7, 0.5 and 0.3, respectively. Broken line demonstrates the bulk density of H 2 (i.e. packing density = 0). Connecting traces are guides for eyes. S-26
Figure S47. Estimated absolute adsorbed amounts of CH 4 in COF-6 (A), COF-5 (B), and COF-102 (C) at 298 K with different packing density. Red, blue, green, and purple symbols represent adsorption branche of the isotherms with the packing density of 1.0, 0.7, 0.5 and 0.3, respectively. Broken line demonstrates the bulk density of CH 4 (i.e. packing density = 0). Connecting traces are guides for eyes. S-27
Figure S48. Estimated absolute adsorbed amounts of CO 2 in COF-6 (A), COF-5 (B), and COF-102 (C) at 298 K with different packing density. Red, blue, green, and purple symbols represent adsorption branche of the isotherms with the packing density of 1.0, 0.7, 0.5 and 0.3, respectively. Broken line demonstrates the bulk density of CO 2 (i.e. packing density = 0). Connecting traces are guides for eyes. S-28
Relationship between absolute hydrogen uptake and absolute methane uptake Figure S49. Relationship between absolute hydrogen (77 K, 70 bar) and methane uptakes (298 K, 70 bar). S-29
Buoyancy correction for adsorbed layer As the reviewer pointed out, it is better if one can perform the buoyancy correction for the adsorbed layer. We have noticed this issue and actually mentioned it in our former report. 1 However, the underestimation is not a fundamental problem for just the gravimetric measurements. That is, even volumetric instruments underestimate the adsorbed amounts, because it is assumed that the void space in the sample cell is constant throughout the experiments. The volume of adsorbate is derived from the adsorbed gas amounts and density of adsorbate (i.e. adsorbed volume = (adsorbed amount)/(adsorbate density)); 2 however, the adsorbate density and the density profiles in the pore cannot be measured by today s technology. Therefore we assumed that the adsorbate density in the pore is same as a liquid density of the adsorbate. As shown in Figures S50-S52, corrected values are greater than original ones; CO 2 and CH 4 uptakes are increased by ca. 10% and 20% in the high pressure region, respectively, while in H 2 isotherms the values are close or even higher than their absolute adsorbed uptakes (i.e. 50%). We don t report these higher values because we are not convinced because of their reliability and for the following additional reasons: (i) It is unlikely that adsorbed molecules, especially H 2 and CH 4, form multi layers; therefore actual adsorbate volume should be smaller than present estimation. (ii) If the degree of underestimation by the gravimetric system is much greater than that by volumetric one, we cannot explain the results presented in Ref. 1. (iii) Several CO 2 and CH 4 isotherms measured on a gravimetric system are also well-reproduced by simulation calculations. 3 (iv) If volumetric data contains similar degree of the deviation, it is not necessary to correct only the gravimetric data. And (v) even if, it is necessary to correct the data, we cannot estimate the adsorbed volume using a volumetric gas adsorption analyzer, indicating that it is meaningless to compare isotherms measured by two different methods. We note that this is a universal problem with routine gas adsorption measurements, however, the methods we employ in this study are standard in the field and have been routinely practiced by zeolite and other scientists long working on porous materials. References: (1) Furukawa, H.; Miller, M. A.; Yaghi, O. M. J. Mater. Chem. 2007, 17, 3197-3204. (2) Sircar, S. Ind. Eng. Chem. Res. 1999, 38, 3670-3682. (3) (a) Walton, K. S.; Millward, A. R.; Dubbeldam, D.; Frost, H.; Low, J. J.; Yaghi, O. M.; Snurr, R. Q. J. Am. Chem. Soc. 2008, 130, 406-407. (b) Duren, T.; Sarkisov, L.; Yaghi, O. M.; Snurr, R. Q. Langmuir 2004, 20, 2683-2689. S-30
Figure S50. Corrected surface excess and absolute adsorbed amounts of H 2 in COF-6 (A), COF-5 (B), and COF-102 (C) at 77 K. Red and blue symbols represent isotherms before and after correction, and circles and squares represent excess and total mass, respectively. Connecting traces are guides for eyes. S-31
Figure S51. Corrected surface excess and absolute adsorbed amounts of CH 4 in COF-6 (A), COF-5 (B), and COF-102 (C) at 298 K. Red and blue symbols represent isotherms before and after correction, and circles and squares represent excess and total mass, respectively. Connecting traces are guides for eyes. S-32
Figure S52. Corrected surface excess and absolute adsorbed amounts of CO 2 in COF-6 (A), COF-5 (B), and COF-102 (C) at 298 K. Red and blue symbols represent isotherms before and after correction, and circles and squares represent excess and total mass, respectively. Connecting traces are guides for eyes. S-33