Organic Anions Facilitate in Situ Synthesis of Mesoporous LTA

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Organic Anion Facilitates In-situ Synthesis of Mesoporous LTA Zeolites Chao Chen, Dong Zhai, Lei Dong, Yanding Wang, Jian Zhang, Yi Liu, Zhuwen Chen, Ya Wang, Wei Qian, and Mei Hong Chem. Mater., Just Accepted Manuscript • DOI: 10.1021/acs.chemmater.8b04433 • Publication Date (Web): 25 Jan 2019 Downloaded from http://pubs.acs.org on January 27, 2019

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Chemistry of Materials

Supporting Information

Organic Anion Facilitates In-situ Synthesis of Mesoporous LTA Zeolites Chao Chen†,§, Dong Zhai‡,§, Lei Dong†, Yanding Wang†, Jian Zhang†, Yi Liu*,‡, Zhuwen Chen†, Ya Wang†, Wei Qian†, Mei Hong*,†,||

†

Guangdong Provincial Key Laboratory of Nano-Micro Materials Research, School of Chemical

Biology & Biotechnology, Peking University Shenzhen Graduate School, Shenzhen 518055, P.R. China. ‡

Materials Genome Institute (MGI), International Centre for Quantum and Molecular Structures

(ICQMS), Department of Physics, Shanghai University (SHU), 333 Nanchen Road, Shanghai 200444, P. R. China. ||

State Key Laboratory of Chemical Oncogenomics, Peking University Shenzhen Graduate School,

Shenzhen 518055, P.R. China.

Table of Content

1.

Materials ............................................................................................................................ 3

2.

Experimental results on small molecule effect on LTA zeolites ....................................... 3

3.

Experimental results on the organic amount in MLTA zeolites and anion amount effect

on MLTA zeolites ................................................................................................................... 15 4.

Simulations on the in situ dementallation pathway ......................................................... 16

5.

Simulations on OMeGA self-assembly in zeolite synthesis condition ............................ 18

Figure S1. Powder XRD patterns of various NaA zeolites synthesized using small molecule additives listed in Table S1. ...............................................................................................................5 Figure S2. SEM images of NaA crystals synthesized using representative small molecules showing the surface feature of single crystals. Scale bar represents 1 μm............................6 Figure S3. Low magnification SEM images of NaA crystals synthesized using representative small molecules showing an array range of crystals. Scale bar represents 1 μm. ...............6 Figure S4. SEM and cross-sectional TEM images of Ala- and isobutyric acid-mediated MLTA zeolites...................................................................................................................................................7 Figure S5. SEM images of TFA- and 2-aminopropan-1-ol -mediated LTA zeolites ....................7 Figure S6. SEM and cross sectional TEM images of 4-methylbenzenesulfonic-acid- and

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Chemistry of Materials 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

phenol-mediated MLTA zeolites .....................................................................................................8 Figure S7. SEM images of 1,1,1,3,3,3-hexafluoropropan-2-ol- and HOBt -mediated MLTA zeolites...................................................................................................................................................8 Figure S8. SEM and cross-sectional TEM images of 2,2-dimethylpropan-1- and 2methylpropan-1-ol -mediated LTA zeolites ..................................................................................9 Figure S9. SEM images of propan-2-ol- and nitrobenzene-mediated LTA zeolites .....................9 Figure S10. SEM and cross-sectional TEM images of 2-methylpropan-1-amine- and 1H-1,2,3triazole-mediated LTA zeolites ..................................................................................................... 10 Figure S11. SEM images of 1H-1,2,3-triazole and 1H-pyrrole-mediated LTA zeolites ........... 10 Figure S12. SEM images of 1H-imidazole-mediated MLTA zeolite ............................................ 11 Figure S13. SEM and cross-sectional TEM images of nitromethane-mediated MLTA zeolite .............................................................................................................................................................. 11 Figure S14. SEM and cross-sectional TEM images of conventional LTA synthesized without additives, and comparative LTA synthesized with the addition of NaCl. ........................... 12 Figure S15. (a) N2 adsorption–desorption isotherms and (b) BJH mesopore size distributions of LTA samples mediated by representative organic oxyanion precursors or oxygencontaining additives (O1-O6) ....................................................................................................... 12 Figure S16. (a) N2 adsorption–desorption isotherms and (b) BJH mesopore size distributions of LTA samples mediated by some organic oxyanion precursors or oxygen-containing additives (O7-O12) .......................................................................................................................... 12 Figure S17. (a) N2 adsorption–desorption isotherms and (b) BJH mesopore size distributions of LTA samples mediated by representative organic nitranion precursors or nitrogencontaining additives (N1-N5) ....................................................................................................... 13 Figure S18. (a) N2 adsorption–desorption isotherms and (b) BJH mesopore size distributions of LTA samples mediated by organic carbanion precursor, in comparison with conventional LTA synthesized without additive and that synthesized with the addition of NaCl .................................................................................................................................................... 13 Figure S19. Effect of small molecule pKa values on generated mesopore volumes represented by Vmeso of NaA crystals. Data points only distribute in quadrant II indicating mesopore generation by OMeGA and in quadrant IV illustrating no significant mesopores by small molecules not deprotonated in-situ. The only exception is that by nitrobenzene probably because its pKa value only represents the carbanion formation tendency, not the oxyanion generation capacity. Low Vmeso values of blank NaA crystals and with NaCl addition were listed in quadrant III suggesting no mesopore formation. ...................................................... 14 Figure S20. Comparison of mesopore size distribution curves for mesoporous LTA mediated by L-alanine obtained from nitrogen physisorption, Ar physisorption (by applying NLDFT and BJH methods on either adsorption or desorption branch), and mercury porosimetry........................................................................................................................................ 14 Figure S21. Relative weight loss in TGA of MLTA samples synthesized with a) L-alanine and (b) phenol collected at different stages: after synthesis, after water washing, and after calcination at 600 °C. The TGA curves for free organics were shown in the same figures for comparison. ................................................................................................................................ 15 Figure S22. SEM images of NaA zeolites shown in Table S2 synthesized in the presence of (ad) alanine employing a molar ratio of 1 Al2O3: 2 SiO2: 120 H2O plus the Na2O: alanine


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ratio listed at the upper right corner of the images, (e-h) phenol employing a molar ratio of 1 Al2O3: 2 SiO2: 120 H2O plus the Na2O: phenol ratio listed at the upper right corner of the images. .................................................................................................................................... 16 Figure S23. 18T cluster models of LTA zeolite. Atoms with ball-and-stick style are relaxed and other atoms are frozen. ................................................................................................................... 16 Figure S24. Potential energy surface of framework Si-O bond elongating of FS in desilication. .............................................................................................................................................................. 17 Figure S25. Energy profiles and reaction paths of desilication (deSi, blue) and dealumination (deAl, red) by NaOH attacking. Values in box are the energy barriers for each reaction step. Only structures in reaction-related region are displayed for clarity. .......................... 18 Figure S26. Plot of the RDG versus the sign(λ2)ρ (left) and NCI isosurfaces correspond to RDG = 0.25 a.u. and a color scale of -0.03 < ρ < 0.02 a.u. (right) for NaOH.............................. 18 Figure S27. Plot of the RDG versus the sign(λ2)ρ (left) and NCI isosurfaces correspond to RDG = 0.25 a.u. and a color scale of -0.03 < ρ < 0.02 a.u. (right) for NaAla configuration A. .............................................................................................................................................................. 19 Figure S28. Plot of the RDG versus the sign(λ2)ρ (left) and NCI isosurfaces correspond to RDG = 0.25 a.u. and a color scale of -0.03 < ρ < 0.02 a.u. (right) for NaAla configuration B. .............................................................................................................................................................. 19 Figure S29. Plot of the RDG versus the sign(λ2)ρ (left) and NCI isosurfaces correspond to RDG = 0.25 a.u. and a color scale of -0.03 < ρ < 0.02 a.u. (right) for NaAla dimer. ................. 19 Figure S30. Plot of the RDG versus the sign(λ2)ρ (left) and NCI isosurfaces correspond to RDG = 0.25 a.u. and a color scale of -0.03 < ρ < 0.02 a.u. (right) for NaAla trimer. ................ 20 Figure S31. Plot of the RDG versus the sign(λ2)ρ (left) and NCI isosurfaces correspond to RDG = 0.25 a.u. and a color scale of -0.03 < ρ < 0.02 a.u. (right) for NaAla tetramer. ............ 20 Figure S32. Plot of the RDG versus the sign(λ2)ρ (left) and NCI isosurfaces correspond to RDG = 0.25 a.u. and a color scale of -0.03 < ρ < 0.02 a.u. (right) for NaAla hexamer. ............ 20 Figure S33. The COM–COM RDFs for Ala-–Ala-, Ala-–Na+, Ala-–OH-, OH-–OH-, OH-–Na+, Ala-–water, OH-–water, and Na+–water...................................................................................... 21 Figure S34. Energy of nNaAla chain as a function of the chain length. The numbers next to the data points represent the number of Na-Ala ion pair (n). The optimized structures of 2NaAla, 8NaAla, and 16NaAla chain model are illustrated in the figure. DREIDING force field with QEq charge scheme was used to describe interatomic and intermolecular interactions. ....................................................................................................................................... 22

1. Materials Chemicals: The organic molecules listed in Table S1 and Table 1 were of analytical grade and used as purchased from China local suppliers without further purification. Inorganic salts of sodium hydroxide and sodium aluminate (38%Na 2O, 50%Al2O3) were purchased from GENERAL REAGENT and Ludox (25% SiO2 aqueous solution) from Qingdao Ocean Co., Ltd.

2. Experimental results on small molecule effect on LTA zeolites 2.1 Overview on the efficacy of small molecules as OMeGA Table S1 Screened small molecule structures and the corresponding NaA zeolite synthetic and texture properties



Additive Entry

symbol:

pKa1)

structure S1

Crystalli zation time (h)

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SBET2)

dmeso3)

Vtotal4)

VMeso5)

Crystallini

(m2·g-1)

(nm)

(cm3·g-1)

(cm3·g-1)

ty6) (%)

FAU content7) (%)

2.31±0.10

20

113

14.73

0.14

0.10

70.4

1.42

4.85±0.10

20

121

14.23

0.13

0.08

64.7

3.08

0.05±0.10

18

141

14.60

0.13

0.08

86.7

2.97

12.88±0.10

20

15

56.01

0.01

0.006

80.9

0.00

35

18

10

11.39

0.01

0.01

106.8

0.00

-0.43±0.50

16

89

18.11

0.13

0.10

57.1

2.70

9.86±0.13

18

124

14.71

0.13

0.09

81.2

2.67

9.75±0.20

18

132

14.04

0.13

0.09

76.5

3.02

7.39±0.58

16

80

14.50

0.10

0.08

74.1

1.66

O1: S2 O2: S3 O3: S4

S5

O4:

N1:

S6 O5: S7

S8

O6:

O7:

S9 O8: S10

O9:

15.24±0.10

16

22

56.49

0.009

0.01

77.1

0.00

S11

O10:

15.10±0.10

20

6.3

65.78

0.009

0.007

89.7

0.00

15.31±0.20

20

8.6

57.90

0.009

0.005

92.7

0.00

8.73±0.70

17

103

14.20

0.14

0.11

78.4

2.87

10.18±0.20

18

70

18.31

0.12

0.096

62.1

1.12

17.00±0.50

20

21

57.02

0.018

0.0095

83.8

0.00

13.89±0.10

16

37

11.07

0.05

0.04

86.7

0.45

10.20±0.10

16

105

8.89

0.09

0.05

66.2

2.17

27.88)

20

35

14.76

0.068

0.055

88.9

0.56

S12

O11:

S13 N2: S14 N3: S15

S16

S17

S18

N4:

N5:

C1:

O12:

S19

No additive

-

20

3.4

11.66

0.007

0.0056

100

0.00

S20

NaCl

-

24

14

18.57

0.037

0.032

74.7

0.00

1)

Scifinder data (Calculated using Advanced Chemistry Development (ACD/Labs) Software V11.02)

2)

BET surface area obtained from N2 adsorption isotherm in the relative pressure range of 0.01-0.20


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3)

Mesopore diameter calculated from the desorption branch using the BJH method

4)

Total pore volume calculated as the amount of N2 adsorbed at P/P0 = 0.98

5)

Mesopore volume calculated as (total pore volume - Vmic obtained from t-Plot method)

6)

Crystallinity measured and calculated based on XRD using blank LTA zeolite synthesized without organics as a reference

7)

FAU content measured and calculated based on XRD using homogenous physical mixture of 10% commercial FAU/ 90% commercial LTA purchased from Acros as a reference

8)

http://ibond.nankai.edu.cn/（Internet Bond-energy Databank (iBonD)

Figure S1. Powder XRD patterns of various NaA zeolites synthesized using small molecule additives listed in Table S1.



Figure S2. SEM images of NaA crystals synthesized using representative small molecules showing the surface feature of single crystals. Scale bar represents 1 μm.

Figure S3. Low magnification SEM images of NaA crystals synthesized using representative small molecules showing an array range of crystals. Scale bar represents 1 μm.


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2.2 SEM and TEM images of NaA crystals synthesized using representative organic oxyanion precursors

Figure S4. SEM and cross-sectional TEM images of Ala- and isobutyric acid-mediated MLTA zeolites

Figure S5. SEM images of TFA- and 2-aminopropan-1-ol -mediated LTA zeolites



Figure S6. SEM and cross sectional TEM images of 4-methylbenzenesulfonic-acid- and phenol-mediated MLTA zeolites

Figure S7. SEM images of 1,1,1,3,3,3-hexafluoropropan-2-ol- and HOBt -mediated MLTA zeolites


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(b Figure S8. SEM and cross-sectional TEM images of 2,2-dimethylpropan-1- and 2-methylpropan-1-ol -mediated LTA zeolites

Figure S9. SEM images of propan-2-ol- and nitrobenzene-mediated LTA zeolites

2.3 SEM and TEM images of NaA crystals synthesized using representative organic nitranion precursors



Figure S10. SEM and cross-sectional TEM images of 2-methylpropan-1-amine- and 1H-1,2,3-triazole-mediated LTA zeolites

Figure S11. SEM images of 1H-1,2,3-triazole and 1H-pyrrole-mediated LTA zeolites


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Figure S12. SEM images of 1H-imidazole-mediated MLTA zeolite

2.4 SEM and TEM images of NaA crystals synthesized using representative carbanion precursor

Figure S13. SEM and cross-sectional TEM images of nitromethane-mediated MLTA zeolite

2.5 SEM and TEM images of comparative NaA crystals synthesized without organic additive or with inorganic NaCl salt addition



No additive 20 hrs; Entry 19

Figure S14. SEM and cross-sectional TEM images of conventional LTA synthesized without additives, and comparative LTA synthesized with the addition of NaCl.

2.6 N2 adsorption–desorption isotherms and the corresponding mesopore size distribution

Figure S15. (a) N2 adsorption–desorption isotherms and (b) BJH mesopore size distributions of LTA samples mediated by representative organic oxyanion precursors or oxygen-containing additives (O1-O6)

Figure S16. (a) N2 adsorption–desorption isotherms and (b) BJH mesopore size distributions of LTA samples mediated by some organic oxyanion precursors or oxygen-containing additives (O7-O12)


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Figure S17. (a) N2 adsorption–desorption isotherms and (b) BJH mesopore size distributions of LTA samples mediated by representative organic nitranion precursors or nitrogen-containing additives (N1-N5)

Figure S18. (a) N2 adsorption–desorption isotherms and (b) BJH mesopore size distributions of LTA samples mediated by organic carbanion precursor, in comparison with conventional LTA synthesized without additive and that synthesized with the addition of NaCl



Figure S19. Effect of small molecule pKa values on generated mesopore volumes represented by V meso of NaA crystals. Data points only distribute in quadrant II indicating mesopore generation by OMeGA and in quadrant IV illustrating no significant mesopores by small molecules not deprotonated in-situ. The only exception is that by nitrobenzene probably because its pKa value only represents the carbanion formation tendency, not the oxyanion generation capacity. Low Vmeso values of blank NaA crystals and with NaCl addition were listed in quadrant III suggesting no mesopore formation.

0.45

dV/dlog(w) Pore Volume (cm3/g)

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

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0.40

DFT(Argon Adsorption) DFT(Nitrogen Adsorption) BJH(Argon Adsorption) BJH(Nitrogen Adsorption) BJH(Argon Desorption) BJH(Nitrogen Desorption) HG Intrusion

0.35 0.30 0.25 0.20 0.15 0.10 0.05 0.00 1

5

10

50

100

Pore Width (nm)

Figure S20. Comparison of mesopore size distribution curves for mesoporous LTA mediated by L-alanine obtained from nitrogen physisorption, Ar physisorption (by applying NLDFT and BJH methods on either adsorption or desorption branch),


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and mercury porosimetry.

3. Experimental results on the organic amount in MLTA zeolites and anion amount effect on MLTA zeolites

Figure S21. Relative weight loss in TGA of MLTA samples synthesized with a) L-alanine and (b) phenol collected at different stages: after synthesis, after water washing, and after calcination at 600 °C. The TGA curves for free organics were shown in the same figures for comparison.

Table S2 Effect of OMEGA amount in the gel on the corresponding MLTA zeolite texture properties OMeGA

Na2O:

SBET a

Alanine

phenol

Vtotal

(nm)

(m ·g )

(m3·g-1)

2:0.5

136

14.27

0.12

0.07

2:1

113

14.73

0.14

0.10

22

49.96

0.05

0.05

1.75:0.5

123

22.63

0.07

0.02

2:0.5

144

17.00

0.12

0.07

2:1

124

14.71

0.13

0.09

22

49.96

0.05

0.00

64

18.07

0.10

0.08

2:1.5

b

1.75:0.5

3

-1

VMeso

(m ·g )

2:1.5

-1

dmeso

OMeGA

b

2

a)

The synthesis solutions employed a molar ratio of 1 Al2O3: 2 SiO2: 120 H2O plus the Na2O: OMeGA ratio as listed.

b)

The synthesis with 1.5 OMeGA led to incomplete crystallization containing mostly amorphous phase as shown in Fig.

S22



Figure S22. SEM images of NaA zeolites shown in Table S2 synthesized in the presence of (a-d) alanine employing a molar ratio of 1 Al2O3: 2 SiO2: 120 H2O plus the Na2O: alanine ratio listed at the upper right corner of the images, (e-h) phenol employing a molar ratio of 1 Al2O3: 2 SiO2: 120 H2O plus the Na2O: phenol ratio listed at the upper right corner of the images.

4. Simulations on the in situ dementallation pathway 4.1 Details of the DFT calculation models In order to decouple the complexity of the system and focus on the key factors in desilication and dealumination, we used the models of all-silica LTA-type zeolite[1] in the DFT calculations. The initial atomic coordinates of LTA zeolite with space group Pm-3m were taken from Carey et al.’s X-ray diffraction Rietveld analysis.[2] The experimental lattice parameter of LTA unit cell is 11.853 Å. All T (T = Si or Al) sites are crystallographically equivalent. A cluster model with 18 TO 4 (T = Si or Al) tetrahedrons (18T), consisting of one eight-member ring (8MR), one six-member ring (6MR), and three fourmember rings (4MR), was cut from the crystal structure of LTA zeolite. The dangling bonds were saturated by hydrogen atoms with optimized Si-H bond length. Five tetrahedrons centered on the attacked T atom are relaxed and other atoms in zeolite framework are frozen. We used all-silica 18T model (Si18T) and 18T model with one framework Al atom and Na+ ion (Al18T) to study desilication and dealumination processes, respectively.

Figure S23. 18T cluster models of LTA zeolite. Atoms with ball-and-stick style are relaxed and other atoms are frozen.


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4.2 Computational methods We used M06-2X exchange-correlation functional[3] and Pople-type 6-311++G** basis set[4] in all DFT calculations. Solvation effects was considered using SMD continuum solvation model [5] with the dielectric constant of water (78.355). Gaussian 09 software[6] was used in the calculations. Cluster models were used to represent LTA zeolite (see SI for more details). For the desilication and dealumination, transition states were located using the synchronous transit-guided quasiNewton (STQN) and Berny algorithm. All transition states were confirmed by vibrational analyses, yielding only one imaginary frequency. We also verified transition states to connect to both reactant and product complexes by intrinsic reaction coordinate (IRC) calculations. For the calculations of Na-Ala clusters, we first used force field-based simulated annealing to obtain the stable structures. DREIDING force field[7] with QEq charge scheme[8] was used to describe interatomic and intermolecular interactions of Na-Ala in simulated annealing. Further structure optimization was performed by DFT calculations for each stable cluster. We used non-covalent interactions (NCI) index[9] to analyze and visualize the weak interactions in Na-Ala clusters. This method is based on the electron density (ρ) and the reduced density gradient (RDG, s). 𝑠=

|∇𝜌| 2(3𝜋 2 )1/3 𝜌4/3

The isosurfaces of the RDG colored by a scale of strength were used to identify non-covalent interactions. The strength is the product of the electron density and the sign of the second eigenvalue (λ2) of the Hessian of the electron density [sign(λ2)ρ] at each point of the isosurface, with the attractive or repulsive character being determined by the sign of λ2. It provides a direct representation and characterization of non-covalent interactions in real space, including van der Waals interactions (vdW), steric clashes (SC), and hydrogen bonds (HBs). Multiwfn 3.3.9

[10]

program was used for NCI

analysis.

4.3 Potential energy surface of framework Si-O bond elongating of FS in desilication We performed flexible scan of the framework Si-O bond breaking in FS to obtain the potential energy surface of framework Si-O bond elongating of FS in desilication by Ala attacking. It is shown that the relative energy reach a plateau when the length of Si-O bond is elongated to the range of 2.5-2.8 Å.

Figure S24. Potential energy surface of framework Si-O bond elongating of FS in desilication.

4.4 Desilication and dealumination by NaOH For comparison, we also studied the desilication and dealumination of LTA zeolite by NaOH pair ion attacking (Figure S25). The desilication and dealumination by NaOH require the energy barriers

Organic Anions Facilitate in Situ Synthesis of Mesoporous LTA

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