Structural Studies of Important Industrial Gases Adsorbed in Zeolites

Matthew Cline Advisors: Craig Brown, Matthew Hudson

Outline • Objectives • Methodology

– Zeolites – SSZ-13 – Synthesis – Adsorption Isotherms – Sample Preparation and Testing

• Results & Discussions – CO2 loaded All Silica CHA – CO2 loaded Li-SSZ-13 – Methane loaded Cu-SSZ-13

• Conclusions

Objectives

• Gas separation and sequestration – Locating adsorption sites – Analyze the site conditions – Determination of materials with appropriate

conditions • Zeolites

Zeolite

• Microporous Material • Aluminosilicate Frame • Uses

– Laundry Detergent – Cat Litter – Catalyst for Cracking – Water Purification – Gas Separation

• 50+ Framework Types – Chabazite (SSZ-13)

Image of Chabazite-Ca from: http://webmineral.com/specimens/picshow.php?id=3054&target=Chabazite-Ca

Chabazite (SSZ-13)

• Rhombohedral • Space Group: R3 m • a, b = 13.548(8) Å c = 15.07(3) Å • α, β = 90°; γ = 120° • Ring sizes: 8, 6 and 4 • Composition of Frame:

– 1 Silicon and Aluminum site – 4 Oxygen sites

Image from: http://izasc.ethz.ch/fmi/xsl/IZA-SC/ftc_fw.xsl?-db=Atlas_main&-lay=fw&-max=25&STC=CHA&-find

Synthesis

• Synthesis of NH4-SSZ-13 • Cation Exchange • Initial Characterization

– Adsorption Isotherms

Raul Lobo’s Group

Comparison of CO2 Adsorption in Chabazites

Adsorption Isotherms Comparison of Gas Adsorption in Cu-SSZ-13

Graphs from Raul Lobo's Group

Sample Preparation

• Degas at 350 °C for 36 hours

• Lab X-ray Diffractometer • Vanadium Can • Closed Cycle Refrigerator • Load Gas (if applicable)

Instrumentation

APS Synchrotron NCNR BT1

Analysis

20 40 60 80 100 120 1400

2000

4000

6000

Inte

nsity

2 θ

Χ2 = 6.833 Fitted wRp = 10.55% Χ2 = 1.370 Fitted wRp = 4.97%

ALL SILICA SSZ-13 No Cation

All Silica 1.0 CO2 Loaded

LI-SSZ-13 +1 Cation

13.57

13.58

13.59

13.6

-0.2 0.3 0.8 1.3

Dis

tanc

e (Å

)

Loading

a & b

14.96

14.98

15

15.02

-0.2 0.3 0.8 1.3

Dis

tanc

e (Å

)

Loading

c

Lattice Constants

Li-SSZ-13 Basic Information

Δ = 0.017 Å

Δ = 0.036 Å

Li-SSZ-13 1.0 CO2 Loading

CO2 Loading

CO2 Placement

0.5 Loading 1.0 Loading 2.20 (6) Å

3.85 (6) Å

2.22 (6) Å

4.103 (12) Å

CU-SSZ-13 2+ Cation

Cu-SSZ-13 0.25 CO2 Loading

Cu-SSZ-13 Lattice Constants

13.535013.540013.545013.550013.555013.560013.5650

0.0 1.0 2.0 3.0 4.0 5.0

Dis

tanc

e (Å

)

Loading

a, b

15.0315.0415.0515.0615.0715.0815.0915.1

0.0 1.0 2.0 3.0 4.0 5.0

Dis

tanc

e (Å

)

Loading

c

Δ = 0.018 Å

Δ = 0.052 Å

Cu-SSZ-13 2.0 Methane Loading

0.25 Loading of N2

Methane Placement

93.2° 0.167 Loading

0.333 Loading

108.3°

0.083 Loading

115.5°

0.667 Loading 116.4°

CONCLUSIONS

CO2 Sites: Relative Strengths

0

2

4

6

0 0.5 1

CO

2 Mol

ecul

es

Loading

Li-SSZ-13

0

2

4

6

0 0.5 1

CO

2 Mol

ecul

es

Loading

Cu-SSZ-13

0

2

4

6

0 0.5 1

CO

2 Mol

ecul

es

Loading

All Silica SSZ-13

Pore SiteWindow SiteCation Site

APS Synchrotron Data

BT1 NCNR Data

Conclusions

• Results – CO2 located in Li-SSZ-13

• In window • Coordinated with lithium

– Methane located in Cu-SSZ-13 • In pore

• Future Work – Finish analysis of other SSZ-13 – Methane locations in other SSZ-13

Acknowledgements

• Advisors: – Craig Brown – Matthew Hudson

• Special Thanks: – Julie Borchers – Wendy Queen

• SURF Directors: – Robert D. Shull – Terrell A. Vanderah