Supporting Information. Flexible-Robust Metal-Organic Framework for Efficient

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1 Supporting Information Flexile-Roust Metal-Organic Framework for Efficient Removal of Propyne from Propylene Lio Li, a,,e,# Rui-Biao Lin,,# Rajamani Krishna, c Xiaoqing Wang, a,e Bin Li, Hui Wu, d Jinping Li, a,e, * Wei Zhou, d, * and Banglin Chen, * a College of Chemistry and Chemical Engineering, Taiyuan University of Technology, Taiyuan , Shanxi, P. R. China Department of Chemistry, University of Texas at San Antonio, One UTSA Circle, San Antonio, TX , United States c Van t Hoff Institute for Molecular Sciences, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands d NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersurg, MD , United States e Shanxi Key Laoratory of Gas Energy Efficient and Clean Utilization, Taiyuan , Shanxi, P. R. China Tale of Contents 1. Experimental section Materials Powder x-ray diffraction experiment and FTIR spectroscopy Neutron diffraction experiment Density-functional theory calculations Single-component adsorption measurements Breakthrough separation experiments Calculation of the separation potential of ELM Fitting of pure component isotherms Isosteric heat of adsorption IAST calculations of adsorption selectivities Transient reakthrough simulations Synthesis and characterization of ELM Crystal structure of ELM Crystallographic data of D 4-loaded ELM adsorption in ELM-12 calculated y DFT-D method Breakthrough curves for / separation Adsorption cycling experiments for ELM Separation cycling experiments for ELM Structural staility experiments for ELM S1

2 1. Experimental section 1.1 Materials [Cu(py)2(OTf)2] (ELM-12): The synthetic method descried y Kondo et al. [1] was improved as follows: A solution of py (10.0 mmol/l, 10.0 ml) in ethanol was carefully layered onto an aqueous solution (10 ml) of Cu(OTf)2 (5 mmol/l) in a watch glass with no stirring. Then, the mixture was placed in a 298 K in cuator for 7 days to give sheet crystals as [Cu(py)2(OTf)2] 2EtOH H2O. Then, the crystals were collected and activated under 10 6 ar at 393 K until no further weight loss was oserved to give [Cu(py)2(OTf)2] as a guest free struture. [Cu(py)2(OTf)2] has 2D structure, which was constructed with Cu 2+ and py as the layer and ridging OTf to integrated into a three-dimensional structure. 1.2 Powder x-ray diffraction experiment and FTIR spectroscopy The crystallinities and phase purities of the samples were measured y powder X-ray diffraction (PXRD) with a Rigaku Mini Flex II X-ray diffractometer employing Cu-Kα radiation operated at 30 kv and 15 ma, scanning over the range 5 40 (2θ) at a rate of 1 /min. Fourier Transform infrared (FTIR) spectroscopy was performed y using an IRAffinity-1 (SHIMADZU) spectrometer. 1.3 Neutron diffraction experiment Powder neutron diffraction data were collected using the BT-1 neutron powder diffractometer at the National Institute of Standards and Technology (NIST) Centre for Neutron Research. A Ge(311) monochromator with a 75 take-off angle, λ = (2) Å, and in-pile collimation of 60 minutes of arc was used. Data were collected over the range of (2θ) with a step size of Fully activated ELM-12 sample was loaded in a vanadium can equipped with a capillary gas line. A closed-cycle He refrigerator was used to control the sample temperature. The are MOF sample was measured first at the temperatures of 298 K. To proe the propyne adsorption locations, a pre-determined pressure (1 ar) of C3D4 was loaded into the sample at room temperature. Diffraction data were then collected on the C3D4-loaded MOF sample. Rietveld structural refinement was performed on the neutron diffraction data using the GSAS package. [2] Refinement on lattice parameters, atomic coordinates, thermal factors, gas molecule occupancies, ackground, and profiles all converge with satisfactory R-factors. Crystallographic data and refinement information are summarized in Tale S1. CCDC contains the supplementary crystallographic data of C3D4-loaded ELM-12. This data can e otained free of charge from the Camridge Crystallographic Data Centre via Density-functional theory calculations Density-functional theory (DFT) calculations were performed using the Quantum-Espresso package. [3] A semi-empirical addition of dispersive forces to conventional DFT was included in the calculation to account for van der Waals S2

3 interactions. [4] We first optimized the structure of ELM-12, the optimized structure agrees well with the reported ELM-12 (Guest-free) structure. [1] C3H4 and C3H6 guest gas molecules were then introduced to various locations of the MOF pore, followed y a full structural relaxation. The static inding energy (at T = 0 K) was calculated using: EB = E(MOF) + E(gas) E(MOF+gas). 1.5 Single-component adsorption measurements The purities of the propyne and propylene are higher than %. Their adsorption isotherms were collected with an Intelligent Gravimetric Analyser (IGA 001, Hiden, UK). Samples were activated overnight under vacuum at 393 K or until no further weight loss was oserved. 1.6 Breakthrough separation experiments The reakthrough curves of were measured on a homemade apparatus for gases mixtures C3H4/C3H6 (1/99) and C3H4/C3H6 (50/50) at 298 K and 1.01 ar. In the separation experiment, ELM-12 ( g) particles with diameters of μm were prepared and packed into Φ mm stainless steel column, and the column was activated under reduced pressure at 393 K overnight. The experimental set-up consisted of two fixed-ed stainless steel reactors. One reactor was loaded with the adsorent, while the other reactor was used as a lank control group to stailize the gas flow. The gas flows were controlled at the inlet y a mass flow meter as 2 ml/min, and a gas chromatograph (TCD-Thermal Conductivity Detector, detection limit 0.1 ppm) continuously monitored the effluent gas from the adsorption ed. Prior to every reakthrough experiment, we activated the sample y flushing the adsorption ed with helium gas for 2 hours at 373 K. Susequently, the column was allowed to equilirate at the measurement rate efore we switched the gas flow. Breakthrough experiments apparatus S3

4 2. Calculation of the separation potential of ELM Fitting of pure component isotherms The experimentally measured excess loadings for C3H4 and C3H6 at temperatures of 273 and 298 K for ELM-12 were fitted with the dual-langmuir-freundlich isotherm model q q A, sat A p 1 A A p A q B, sat B p 1 with T-dependent parameters A, and B B B p B A A0 EA EB exp ; B B0 exp RT RT The parameters are provided in Tale S Isosteric heat of adsorption The inding energies of C3H4, and C3H6 for ELM-12 are reflected in the isosteric heat of adsorption (Figure S2), Qst, defined as Q st 2 ln p RT T q These values were determined y analytic differentiation of the pure component isotherm fits. 2.3 IAST calculations of adsorption selectivities In order to estalish the feasiility of C3H4/C3H6 separations we performed calculations using the ideal adsored solution theory (IAST) of Myers and Prausnitz. [5] The adsorption selectivities and uptakes were determined for 1/99 (Figure 1e) and 50/50 C3H4/C3H6 (Figure S3) mixtures at 298 K. 2.4 Transient reakthrough simulations The performance of industrial fixed ed adsorers is dictated y a comination of adsorption selectivity and uptake capacity. For a proper comparison of various MOFs, we perform transient reakthrough simulations using the simulation methodology descried in the literature (Figure S8). [6] For the reakthrough simulations, the following parameter values were used: length of packed ed, L = 0.3 m; voidage of packed ed, = 0.4; superficial gas velocity at inlet, u = 0.04 m/s. The framework density of ELM-12 is 1406 kg m -3. The transient reakthrough simulation results are presented in terms of a dimensionless time,, defined y dividing the actual time, t, y the characteristic time, L. u S4

5 Notation A Langmuir-Freundlich constant for species i at adsorption site A, ia Pa B Langmuir-Freundlich constant for species i at adsorption site B, ib Pa ci molar concentration of species i in gas mixture, mol m -3 ci0 molar concentration of species i in gas mixture at inlet to adsorer, mol m -3 E energy parameter, J mol -1 L length of packed ed adsorer, m pi partial pressure of species i in mixture, Pa pt total system pressure, Pa qi component molar loading of species i, mol kg -1 Qst isosteric heat of adsorption, J mol -1 t time, s T asolute temperature, K u superficial gas velocity in packed ed, m s -1 Greek letters voidage of packed ed, dimensionless Freundlich exponent, dimensionless framework density, kg m -3 time, dimensionless References [1] Kondo, A.; Noguchi, H.; Carlucci, L.; Proserpio, D. M.; Ciani, G.; Kajiro, H.; Oha, T.; Kanoh, H.; Kaneko, K. J. Am. Chem. Soc. 2007, 129, [2] Larson, A. C.; Von Dreele, R. B. General Structure Analysis System, Report LAUR ; Los Alamos National Laoratory: Los Alamos, NM, [3] Giannozzi, P.; Baroni, S.; Bonini, N.; Calandra, M.; Car, R.; Cavazzoni, C.; Ceresoli, D.; Chiarotti, G. L.; Cococcioni, M.; Dao, I.; Dal Corso, A.; de Gironcoli, S.; Faris, S.; Fratesi, G.; Geauer, R.; Gerstmann, U.; Gougoussis, C.; Kokalj, A.; Lazzeri, M.; Martin-Samos, L.; Marzari, N.; Mauri, F.; Mazzarello, R.; Paolini, S.; Pasquarello, A.; Paulatto, L.; Sraccia, C.; Scandolo, S.; Sclauzero, G.; Seitsonen, A. P.; Smogunov, A.; Umari, P.; Wentzcovitch, R. M. J. Phys.: Condens. Matter 2009, 21, [4] Barone, V.; Casarin, M.; Forrer, D.; Pavone, M.; Sami, M.; Vittadini, A. J. Comput. Chem. 2009, 30, 934. [5] Myers, A. L.; Prausnitz, J. M. A.I.Ch.E.J. 1965, 11, 121. [6] Krishna, R. RSC Adv. 2015, 5, S5

6 Intensity (a.u.) Intensity (a.u.) 3. Synthesis and characterization of ELM Crystal structure of ELM-12. [Cu(py) 2 (OTf) 2 ] 2EtOH H 2 O [Cu(py) 2 (OTf) 2 ] Synthesized Activited Simulated Simulated theta theta (a) () Cavity Ι Cavity II a c Figure S1. Powder X-ray diffraction (PXRD) patterns of the synthesized and activated ELM-12 samples are very similar to simulated structural data, which further confirm the phase purity of these samples. (a-) ELM-12 consists of a rigid square-grid copper ipyridine scaffold with dynamic dangling OTf groups. After the guest removal, ELM-12 still shows porosity with two kinds of cavities (cavity I and II) (Cu, green; C, gray; O, red; H, white; S, yellow; F, lue). S6

7 IAST Selectivity Q st (kj/mol) Calculation of the separation potential of ELM Adsorption amount (cm 3 /g) Figure S2. Adsorption heat of C3H4 (red) and C3H6 (lue) for ELM-12, respectively. 100 : 50% : 50% Total gas pressure (kpa) Figure S3. IAST selectivity of ELM-12 for C3H4/C3H6 (50/50) mixtures at 298 K. S7

8 Intensity Uptakes (mmol/g) Pressure (kpa) Figure S4. Mixture adsorption isotherms predicted y IAST of ELM-12 for C3H4/C3H6 (1/99) mixtures at 298 K. 3.2 Crystallographic data of C3D4-loaded ELM os. cal R p = , R wp = theta Figure S5. Experimental (circles), calculated (line), and difference (line elow oserved and calculated patterns) powder neutron diffraction profiles for a C3D4-loaded sample of ELM-12 measured at 298 K. Goodness of fit parameters of the Rietveld refinement are shown as insets. S8

9 Structural comparison of guest-free and C3D4-loaded ELM-12 Guest-free C3D4-loaded c c Cavity Ι Cavity II 4.62 Å 5.58 Å Figure S6. The two preferential C3D4 inding sites and structure-change of ELM-12, as determined y neutron powder diffraction. Cavity II has slightly expansion from Å 3 to Å 3 after the C3D4 adsorption, which indicates the relatively strong host-guest interaction etween C3D4 and ELM-12. S9

10 4. C3H6 adsorption in ELM-12 calculated y DFT-D method Å Site I 4.05 Å Site II 4.43 Å Figure S7. First-principles DFT-D-calculated C3H6 inding sites (the nearest H O distance: site I ~2.70 Å; site II ~ Å) in ELM-12. The calculated static inding energies are ~32.3 (site I) and 25.6 kj/mol (site II) for the two adsorption sites, respectively. Dynamic adsorption on ELM s 239s M t /M e Dynamic adsorption on ELM Time (s) Figure S8. C3H4 and C3H6 dynamic adsorption on ELM-12 at 298 K and 1 ar. The results showed that C3H4 and C3H6 have the similar adsorption equilirium time, the difference of diffusion rates of C3H4 and C3H6 is negligile. Therefore, high C3H4/C3H6 selectivity can e mainly attriuted to the inding and sieving effect of ELM-12. S10

11 5. Breakthrough curves for C3H4/C3H6 separation : 1% : 99% C A /C o Dimensionless time (t) Figure S9. Simulated column reakthrough curves for C3H4/C3H6 (1/99) mixtures separation. C A /C K % 10 ppm (50 %) (50 %) Time (min) Figure S10. Experimental reakthrough curves of C3H4/C3H6 (50/50) mixtures separation for ELM-12 materials at 298 K and 1.01 ar. S11

12 1.0 C A /C CO 2 (50 ppm) C 2 (50 ppm) H 8 (100 ppm) (98.98 %) (1 %) Time (min) Figure S11. Experimental reakthrough curves for separation of (1/98.98/0.01/0.005/ 0.005) C3H4/C3H6/C3H8/C2H4/CO2 mixtures at 298 K and 1.01 ar. S12

13 6. Adsorption cycling experiments for ELM-12 (a) adsorption (cm 3 /g) () adsorption (cm 3 /g) Cycles Cycles Figure S12. C3H4 (a) and C3H6 () adsorption cycles for ELM-12. After each adsorption process, sample was evacuated under 10-6 ar for 30 minutes. S13

14 7. Separation cycling experiments for ELM C A /C 0 Intensity (a.u.) (a) / (1:99) mixture Separation cycles Cycle 1 Cycle 10 Cycle () Time (min) After separation cycles After adsorption cycles Activited Sample theta Figure S13. (a) Cycling column reakthrough curves of C3H4/C3H6 separation (1/99) for ELM-12 at 298 K and 1 ar. The reakthrough experiments were carried out at a flow rate of 2 ml/min. Regeneration with He flow (100 ml/min) for 2 hours at 323 K. () PXRD patterns of ELM-12 samples after adsorption and separation cycles. S14

15 Asorance Intensity (a.u.) 8. Structural staility experiments for ELM-12 (a) Aging sample Fresh sample () Uptakes (cm 3 /g) Fresh sample Aging sample theta Pressure (ar) (c) Aging sample (d) Fresh sample C A /C Wavenumer (cm -1 ) Fresh sample Aging sample Time (min) Figure S14. (a) PXRD, () C3H4 adsorption, (c) FTIR spectroscopy, and (d) reakthrough experiment of C3H4/C3H6 (1/99) mixture for ELM-12 samples (fresh sample and two-years aging sample), respectively. S15

16 Tale S1. Comparison of the crystallographic and refinement parameters for guest-free and C3D4-loaded ELM-12. Crystal data ELM-12 (Guest-free) # ELM-12 (D 4) System Monoclinic Monoclinic Space group C2/c C2/c MF C 22H 16CuF 6N 4O 6S 2 C 24H 16CuD 3F 6N 4O 6S 2 FW a/å /Å c/å α/ o β/ o γ/ o Volume/Å Z 8 8 Density/g/cm Theoretical pore volume/cm 3 /g a a Refinement indices R 1 = , wr 2 = R p = , R wp = a Calculated ased on the MOF crystal structures using PLATON software. # Parameters from Kondo, A. et al. J. Am. Chem. Soc. 2007, 129, Tale S2. Comparison of porosity parameters for guest-free, C3D4-loaded (298 K) and N2-loaded (77 K) ELM-12. Crystal data ELM-12 (Guest-free) # ELM-12 (D 4) ELM-12 (N 2) # Theoretical pore volume/cm 3 /g Density/g/cm Porosity 20.5% 20.4% 38 % # Kondo, A. et al. J. Am. Chem. Soc. 2007, 129, Tale S3. Dual-Langmuir-Freundlich fitting parameters for C3H4 and C3H6 isotherms. Site A Site B q A,sat A0 E A A q B,sat B0 E B B mol kg -1 i Pa kj mol -1 dimensionless mol kg -1 i Pa kj mol -1 dimensionless S16