SSZ-13 Crystallization by Particle Attachment and Deterministic ...
Supporting Information for SSZ-13 Crystallization by Particle Attachment and Deterministic Pathways to Crystal Size Control Manjesh Kumar 1, Helen Luo 2, Yuriy Román-Leshkov 2, Jeffrey D. Rimer 1* 1 2
University of Houston, Chemical and Biomolecular Engineering, Houston, TX 77204 Massachusetts Institute of Technology, Chemical Engineering, Cambridge, MA 02139 *Correspondence sent to [email protected]
List of Supporting Information Figures and Tables Figure S1: XRD patterns of as synthesized SSZ-13 and a reference pattern for SSZ-13 zeolite Figure S2: AFM height profiles of crystal surface features on a SSZ-13 control sample Figure S3: SEM images of WLP precursors during periodic stages of hydrothermal treatment Figure S4: SEM images showing WLP precursors on the surface of SSZ-13 crystals Figure S5: SEM images of crystalline samples at different heating times Figure S6: TEM and SAED pattern of amorphous WLP precursors Figure S7: Elemental analysis of solids and supernatant extracted from growth solutions Figure S8: DLS measurements of precursors in supernatant solutions during periodic stages of heating Figure S9: SAXS patterns of the supernatant extracted from growth solutions Figure S10: Effects of alternative growth modifiers on SSZ-13 crystal size and morphology Figure S11: SEM images of WLP precursors at early stages of heating in the presence of PEIM Figure S12: XRD patterns of SSZ-13 crystals prepared in the presence of PEIM Figure S13: 27Al NMR measurements of tetrahedral and octahedral aluminium Figure S14: SEM images and XRD patterns of SSZ-13 crystals prepared in the presence of CTAB Figure S15: TGA curves of SSZ-13 crystals prepared in the absence and presence of polymers Figure S16: AFM topographical surface features of a SSZ-13 crystal prepared with PDDAC Figure S17: XRD patterns of SSZ-13 crystals prepared in the presence of PDDAC Figure S18: XRD patterns of products during periodic stages of heating in the presence of PDDAC Figure S19: SEM image and XRD patterns of SSZ-13 crystals prepared using modifier combinations Table S1: Ar adsorption/desorption t-plot analysis for SSZ-13 crystals with and without modification S1
Figure S1. Powder XRD pattern of an as synthesized SSZ-13 control sample (top pattern) compared to a reference (bottom pattern) of SSZ-13 obtained from the International Zeolite Association (IZA) structure database.
Figure S2. Representative atomic force microscopy (AFM) data of an as synthesized SSZ-13 crystal surface after synthesis for 6 days at 180°C (control sample). (A) 3-dimensional (3D) height mode of a crystal surface. (B) Amplitude mode image of the same surface. (C) Height profiles measured along the dashed lines (i and ii) in panel B. Heights of surface features correspond to macrosteps of approximately 10 – 20 nm. These profiles have been arbitrarily shifted in the y-axis for improved visual clarity.
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Figure S3. Scanning electron micrographs of amorphous worm-like particle (WLP) precursors at early times during hydrothermal treatment: (A and B) WLPs after 12 h; (C and D) WLPs after 24 h of heating at 180°C.
Figure S4. Scanning electron micrographs of a partially-crystalline SSZ-13 sample taken after 42 h of heating at 180°C. Images reveal the presence of WLPs on crystal surfaces due to either aggregation during SEM sample preparation or their attachment in situ during crystallization. S3
Figure S5. SEM images of SSZ-13 crystals after different heating times. There are three images shown for each time to highlight different populations of crystals in the final product. (A – C) A sample after 42 h of heating at 180°C is comprised of large spheroidal crystals surrounded by amorphous WLPs. (D – F) A sample after 48 h of heating is completely crystalline (see XRD patterns in Figure 2E) and is comprised of two general populations of crystals (small and large) that are spheroidal and appear to be aggregates. (G – I) A sample after 3 days of heating also contains two populations of crystal size. Smaller crystals are less aggregated and develop a cubic habit with increased heating time.
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Figure S6. (A) TEM image of a worm-like particle (WLP) after 36 h of heating at 180°C. (B) Selected area electron diffraction (SAED) pattern reveals that WLPs are amorphous, which is consistent with the powder XRD pattern of extracted WLPs.
Figure S7. Elemental analysis of the solids (top plot) and liquid supernatant (bottom plot) from growth solutions at periodic times during hydrothermal treatment. There is only a marginal change in the silicon and aluminium weight percentages of solids, which account for both amorphous and crystalline phases in the extracted samples. The molar Si/Al ratio (SAR) was obtained by both ICP-OES and EDX. The SAR of the solids is constant with heating time, suggesting the overall chemical composition of WLPs is similar to that of the SSZ-13 crystalline product. Conversely, there is an increase in the SAR of the liquid supernatant with heating time, indicating a rise in silica concentration over the course of nucleation and crystal growth. Error bars equal two standard deviations. S5
Figure S8. Dynamic light scattering (DLS) measurements of supernatant solutions obtained after heating a SSZ-13 growth solution for 12, 24, 36, and 42 h at 180°C. The solutions were centrifuged and filtered with a 0.2 m membrane prior to DLS analysis. The hydrodynamic diameter DH of particulates increases linearly with heating time (in the size range DH > 80 nm). CONTIN analysis reveals a single particle size distribution that agrees with the effective diameter measured by the method of cumulants. We did not observe the presence of particles with sizes less than 80 nm.
Figure S9. Small-angle X-ray scattering (SAXS) patterns of supernatant solutions that were removed after 36 and 42 h of hydrothermal treatment. Two separate solutions, labelled S1 and S2, were analyzed for reproducibility. The supernatant solutions were filtered with a 0.2-m membrane prior to analysis. A measurement of DI water was used as a background that was subtracted from each sample. The large degree of fluctuations in intensity is attributed to low signal-to-noise ratios, which indicates there are few particulates in the supernatant solution. SAXS patterns contain no trace of particles within the size range 1 – 20 nm (i.e., equal to the size of small nanoparticles on SSZ-13 crystal surfaces that are observed in cryo-TEM images; see Figure 5). S6
Figure S10. Summary of alternative modifiers that were tested in the synthesis of SSZ-13. For each modifier we list the chemical name, molecular formula, molecular weight, chemical structure, and quantity used in the synthesis. Representative SEM images for each sample are provided (each inset highlights a single crystal). The overall effect of these modifiers was not significant relative to crystals prepared in the absence of modifier (control sample).
Figure S11. Scanning electron micrograph of amorphous worm-like particles (WLPs) extracted from a SSZ-13 growth solution after 45 h of heating at 180°C in the presence of 1.6 wt% PEIM.
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Figure S12. Powder XRD patterns of SSZ-13 samples prepared in the presence of PEIM at different weight percentages: (i) 0 wt% (control sample), (ii) 1.0 wt%, (iii) 1.6 wt%, and (iv) 3.2 wt%. The highest PEIM concentration resulted in the formation of an impurity (peaks labelled with asterisks). This impurity closely matches zeolite MFI. XRD patterns were arbitrarily shifted along the y-axis for visual clarity.
Figure S13. 27Al NMR spectra of the control (green curve) and samples prepared with either PEIM (blue curve) or PDDAC (red curve). The spectra indicate the presence of both tetrahedral (Altet) and octahedral (Aloct) aluminium. The low intensity of the latter indicates that there is very little extra-framework Al in SSZ-13 samples (see Table 2 in the manuscript). S8
Figure S14. Scanning electron micrographs of SSZ-13 samples prepared in the presence of CTAB at different modifier concentrations: (A and D) 2.5 wt%, (B and E) 5 wt%, and (C and F) 7.5 wt% CTAB. Images A – C correspond to as synthesized samples, whereas images D – F are the same samples after calcination at 550°C to remove residual CTAB and OSDA. (G) Powder XRD patterns of the samples in panels A – F with notation X-Y, where X = wt% CTAB and Y = AS (as synthesized) or C (calcined). Impurity peaks are labelled with an asterisk. A control sample of pure SSZ-13 prepared in the absence of CTAB is included for reference.
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Figure S15. Thermogravimetric (TGA) analysis of SSZ-13 samples prepared in the absence (control, red line) and in the presence of polymers: PDDAC (0.5 wt%, blue line) and PEIM (1.6 wt%, green line). TGA data were obtained using a 2°C/min temperature ramp rate under the constant flow of N2 gas.
Figure S16. AFM topographical images of representative surface features on a SSZ-13 crystal prepared with PDDAC. All images were measured in air using tapping mode. (A) Amplitude mode image revealing the presence of a crack on the surface. (B) Amplitude mode image showing a single hillock with a deposit located at the center of what appears to be a screw dislocation. (C) 3D height mode image shows the presence of steps (and screw dislocations) that are characteristic of classical layer-by-layer growth. S10
Figure S17. Powder XRD patterns of SSZ-13 samples prepared in the (i) absence and (ii) presence of 0.5 wt% PDDAC.
Figure S18. (A) Powder XRD patterns of SSZ-13 samples prepared with PDDAC that were removed from the oven at various times: 24, 28, 29, 30, and 72 h. The patterns are arbitrarily shifted in the y-axis for improved visual clarity. (B) A magnified view of the 29 h pattern reveals the presence of residual amorphous material (indicated by the dashed oval). S11
Figure S19. (A) Scanning electron micrograph of SSZ-13 crystals prepared with a binary combination of PDDAC (0.35 wt%) and PEIM (1.6 wt%). (B) Powder XRD patterns of SSZ-13 crystals prepared in the presence of the following binary combinations (and weight percentages) of modifiers: (i) PDDAC (0.5 wt%) and PEIM (1.6 wt%), (ii) PDDAC (0.5 wt%) and D61,2(13.3 wt%), and (iii) PDDAC (0.35 wt%) and PEIM (1.6 wt%).
Table S1. t-plot analysis of SSZ-13 samples using Ar adsorption/desorption data.
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University of Houston, Chemical and Biomolecular Engineering, Houston, TX 77204 Massachusetts Institute of Technology, Chemical Engineering, Cambridge, MA 02139 *Correspondence sent to [email protected]
List of Supporting Information Figures and Tables Figure S1: XRD patterns of as synthesized SSZ-13 and a reference pattern for SSZ-13 zeolite Figure S2: AFM height profiles of crystal surface features on a SSZ-13 control sample Figure S3: SEM images of WLP precursors during periodic stages of hydrothermal treatment Figure S4: SEM images showing WLP precursors on the surface of SSZ-13 crystals Figure S5: SEM images of crystalline samples at different heating times Figure S6: TEM and SAED pattern of amorphous WLP precursors Figure S7: Elemental analysis of solids and supernatant extracted from growth solutions Figure S8: DLS measurements of precursors in supernatant solutions during periodic stages of heating Figure S9: SAXS patterns of the supernatant extracted from growth solutions Figure S10: Effects of alternative growth modifiers on SSZ-13 crystal size and morphology Figure S11: SEM images of WLP precursors at early stages of heating in the presence of PEIM Figure S12: XRD patterns of SSZ-13 crystals prepared in the presence of PEIM Figure S13: 27Al NMR measurements of tetrahedral and octahedral aluminium Figure S14: SEM images and XRD patterns of SSZ-13 crystals prepared in the presence of CTAB Figure S15: TGA curves of SSZ-13 crystals prepared in the absence and presence of polymers Figure S16: AFM topographical surface features of a SSZ-13 crystal prepared with PDDAC Figure S17: XRD patterns of SSZ-13 crystals prepared in the presence of PDDAC Figure S18: XRD patterns of products during periodic stages of heating in the presence of PDDAC Figure S19: SEM image and XRD patterns of SSZ-13 crystals prepared using modifier combinations Table S1: Ar adsorption/desorption t-plot analysis for SSZ-13 crystals with and without modification S1
Figure S1. Powder XRD pattern of an as synthesized SSZ-13 control sample (top pattern) compared to a reference (bottom pattern) of SSZ-13 obtained from the International Zeolite Association (IZA) structure database.
Figure S2. Representative atomic force microscopy (AFM) data of an as synthesized SSZ-13 crystal surface after synthesis for 6 days at 180°C (control sample). (A) 3-dimensional (3D) height mode of a crystal surface. (B) Amplitude mode image of the same surface. (C) Height profiles measured along the dashed lines (i and ii) in panel B. Heights of surface features correspond to macrosteps of approximately 10 – 20 nm. These profiles have been arbitrarily shifted in the y-axis for improved visual clarity.
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Figure S3. Scanning electron micrographs of amorphous worm-like particle (WLP) precursors at early times during hydrothermal treatment: (A and B) WLPs after 12 h; (C and D) WLPs after 24 h of heating at 180°C.
Figure S4. Scanning electron micrographs of a partially-crystalline SSZ-13 sample taken after 42 h of heating at 180°C. Images reveal the presence of WLPs on crystal surfaces due to either aggregation during SEM sample preparation or their attachment in situ during crystallization. S3
Figure S5. SEM images of SSZ-13 crystals after different heating times. There are three images shown for each time to highlight different populations of crystals in the final product. (A – C) A sample after 42 h of heating at 180°C is comprised of large spheroidal crystals surrounded by amorphous WLPs. (D – F) A sample after 48 h of heating is completely crystalline (see XRD patterns in Figure 2E) and is comprised of two general populations of crystals (small and large) that are spheroidal and appear to be aggregates. (G – I) A sample after 3 days of heating also contains two populations of crystal size. Smaller crystals are less aggregated and develop a cubic habit with increased heating time.
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Figure S6. (A) TEM image of a worm-like particle (WLP) after 36 h of heating at 180°C. (B) Selected area electron diffraction (SAED) pattern reveals that WLPs are amorphous, which is consistent with the powder XRD pattern of extracted WLPs.
Figure S7. Elemental analysis of the solids (top plot) and liquid supernatant (bottom plot) from growth solutions at periodic times during hydrothermal treatment. There is only a marginal change in the silicon and aluminium weight percentages of solids, which account for both amorphous and crystalline phases in the extracted samples. The molar Si/Al ratio (SAR) was obtained by both ICP-OES and EDX. The SAR of the solids is constant with heating time, suggesting the overall chemical composition of WLPs is similar to that of the SSZ-13 crystalline product. Conversely, there is an increase in the SAR of the liquid supernatant with heating time, indicating a rise in silica concentration over the course of nucleation and crystal growth. Error bars equal two standard deviations. S5
Figure S8. Dynamic light scattering (DLS) measurements of supernatant solutions obtained after heating a SSZ-13 growth solution for 12, 24, 36, and 42 h at 180°C. The solutions were centrifuged and filtered with a 0.2 m membrane prior to DLS analysis. The hydrodynamic diameter DH of particulates increases linearly with heating time (in the size range DH > 80 nm). CONTIN analysis reveals a single particle size distribution that agrees with the effective diameter measured by the method of cumulants. We did not observe the presence of particles with sizes less than 80 nm.
Figure S9. Small-angle X-ray scattering (SAXS) patterns of supernatant solutions that were removed after 36 and 42 h of hydrothermal treatment. Two separate solutions, labelled S1 and S2, were analyzed for reproducibility. The supernatant solutions were filtered with a 0.2-m membrane prior to analysis. A measurement of DI water was used as a background that was subtracted from each sample. The large degree of fluctuations in intensity is attributed to low signal-to-noise ratios, which indicates there are few particulates in the supernatant solution. SAXS patterns contain no trace of particles within the size range 1 – 20 nm (i.e., equal to the size of small nanoparticles on SSZ-13 crystal surfaces that are observed in cryo-TEM images; see Figure 5). S6
Figure S10. Summary of alternative modifiers that were tested in the synthesis of SSZ-13. For each modifier we list the chemical name, molecular formula, molecular weight, chemical structure, and quantity used in the synthesis. Representative SEM images for each sample are provided (each inset highlights a single crystal). The overall effect of these modifiers was not significant relative to crystals prepared in the absence of modifier (control sample).
Figure S11. Scanning electron micrograph of amorphous worm-like particles (WLPs) extracted from a SSZ-13 growth solution after 45 h of heating at 180°C in the presence of 1.6 wt% PEIM.
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Figure S12. Powder XRD patterns of SSZ-13 samples prepared in the presence of PEIM at different weight percentages: (i) 0 wt% (control sample), (ii) 1.0 wt%, (iii) 1.6 wt%, and (iv) 3.2 wt%. The highest PEIM concentration resulted in the formation of an impurity (peaks labelled with asterisks). This impurity closely matches zeolite MFI. XRD patterns were arbitrarily shifted along the y-axis for visual clarity.
Figure S13. 27Al NMR spectra of the control (green curve) and samples prepared with either PEIM (blue curve) or PDDAC (red curve). The spectra indicate the presence of both tetrahedral (Altet) and octahedral (Aloct) aluminium. The low intensity of the latter indicates that there is very little extra-framework Al in SSZ-13 samples (see Table 2 in the manuscript). S8
Figure S14. Scanning electron micrographs of SSZ-13 samples prepared in the presence of CTAB at different modifier concentrations: (A and D) 2.5 wt%, (B and E) 5 wt%, and (C and F) 7.5 wt% CTAB. Images A – C correspond to as synthesized samples, whereas images D – F are the same samples after calcination at 550°C to remove residual CTAB and OSDA. (G) Powder XRD patterns of the samples in panels A – F with notation X-Y, where X = wt% CTAB and Y = AS (as synthesized) or C (calcined). Impurity peaks are labelled with an asterisk. A control sample of pure SSZ-13 prepared in the absence of CTAB is included for reference.
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Figure S15. Thermogravimetric (TGA) analysis of SSZ-13 samples prepared in the absence (control, red line) and in the presence of polymers: PDDAC (0.5 wt%, blue line) and PEIM (1.6 wt%, green line). TGA data were obtained using a 2°C/min temperature ramp rate under the constant flow of N2 gas.
Figure S16. AFM topographical images of representative surface features on a SSZ-13 crystal prepared with PDDAC. All images were measured in air using tapping mode. (A) Amplitude mode image revealing the presence of a crack on the surface. (B) Amplitude mode image showing a single hillock with a deposit located at the center of what appears to be a screw dislocation. (C) 3D height mode image shows the presence of steps (and screw dislocations) that are characteristic of classical layer-by-layer growth. S10
Figure S17. Powder XRD patterns of SSZ-13 samples prepared in the (i) absence and (ii) presence of 0.5 wt% PDDAC.
Figure S18. (A) Powder XRD patterns of SSZ-13 samples prepared with PDDAC that were removed from the oven at various times: 24, 28, 29, 30, and 72 h. The patterns are arbitrarily shifted in the y-axis for improved visual clarity. (B) A magnified view of the 29 h pattern reveals the presence of residual amorphous material (indicated by the dashed oval). S11
Figure S19. (A) Scanning electron micrograph of SSZ-13 crystals prepared with a binary combination of PDDAC (0.35 wt%) and PEIM (1.6 wt%). (B) Powder XRD patterns of SSZ-13 crystals prepared in the presence of the following binary combinations (and weight percentages) of modifiers: (i) PDDAC (0.5 wt%) and PEIM (1.6 wt%), (ii) PDDAC (0.5 wt%) and D61,2(13.3 wt%), and (iii) PDDAC (0.35 wt%) and PEIM (1.6 wt%).
Table S1. t-plot analysis of SSZ-13 samples using Ar adsorption/desorption data.
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