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Engineering Accessible Adsorption Sites in Metal Organic Frameworks for CO2 Capture

Saki T. Golafale, Kennedi Trice, Taylor Sledge

Dr. Conrad W. Ingram (PI), Dr. Tandabany C. Dinadayalane (Co-PI)Department of Chemistry, Clark Atlanta University, Atlanta, GA

30314

DOE contract No.: DE-FE00229522017 Crosscutting Research & Rare Earth Elements Portfolios

Review March 20-23, 2017 Pittsburgh, PA

1

• Background• Research goal and objectives • Progress

• Diaza-crown ether MOFs

• Ultra large pore stilbene based MOFs

• Stilbene and pyrazine based MOFs

• CO2 adsorption studies• Summary• Acknowledgement

2

Post-combustion Capture: capturing carbon dioxide from flue gas after fossil fuel combustion

~14% CO2 captured from flue gas

Current techniques pursued • adsorption on a solid

• hybrid processes, such as adsorption/membrane systems

• absorption into a liquid

Flue gas contains about 15% of CO2, 75% of N2, 5% of H2O, 3% of O2,

3

Drawback large amounts of heat are needed to release absorbed CO2

amine is corrosive and unstable, and the liquid is hard to handle.

4

state of the art technology

Required characteristics for solid adsorbents

• High storage capacity,

• Excellent selectivity over other gases,

• Chemically stable under flue gas of power plants,•• Easy to regenerate with minimal energy input, and•• Easily synthesized with low capital cost

5

• Activated carbon

• Zeolites and other inorganic porous materials

• Metal-organic frameworks

Unique properties of MOFs• Highly crystalline nature• Permanent porosity• Uniformed pore-size and large surface area (> 5,000 m2/g)• Tunable chemistry

6

Metal ion + Organic linker MOF material

HO

OHHO

O O

O

Ditopic linker tritopic linker polytopic linker

Examples of Metal salts

Mg(NO3)2 . 6H2O

Zn(NO3)2 . 6H2O

ZrCl4

Metal salts

Examples of organic linkers

7

GoalTo develop metal organic framework (MOFs) materials with improved sites accessibility, thus enhance their CO2 adsorption and selectivity properties

Objectives• To synthesize MOFs with metal ions adsorption sites in more accessible

locations

• To synthesize MOFs with nitrogen containing-ligand/linker as a possible improved alternative to amine-functionalized

• To understand the nature of the adsorption sites and mechanism(s) by computational studies relevant to the adsorption of CO2 within our metal organic frameworks

8

3D interpenetrated Cobalt MOF

+ Co2+

9

Synthesis of nitrogen diaza-crown containing MOFs with metal in center for CO2 adsorption

Ongoing work

3D MOFs using diaza crown ether ligand and with metal within center of crown ether but the structure is nonporous

10

Summary of diaza-crown ether MOFs

O

OHO

OH

HO O

OHO

NH2

H2N

HO O

OHO

NO2

O2N

N

N

OH

O

HO

O

Stilbene linkers Pyrazine linkers

• Rigid or flexible MOFs• Non-interpenetration in MOFs

11

MOFs from stilbene and pyrazine linkers

O

OHO

OH

Mathis II, Stephan R., Saki T. Golafale, John Bacsa, Alexander Steiner, Conrad W. Ingram, F. Patrick Doty, Elizabeth Auden, and Khalid Hattar. Dalton Transactions 46, no. 2 (2017): 491-500.

Non-interpenetrating structure

Ultra-large pores (dimensions of 23 Å x 12 Å)

Accessible channels

Diamond-shaped open framework

+ Ln3+

12

Stilbene lanthanide MOFs

0 5 10 15 20 25 30 35 40 45 50 550

160003200048000

06100

1220018300

05700

1140017100

0170034005100

Cou

nts

2 Theta

TmSDC

TmSDCH2O

TmSDCMeOH

TmSDCCH3Cl3

X-ray diffraction patterns of solvent exchanged stilbene lanthanide MOFs

Framework could adjust depending on solvent used

13

CO2 adsorption analysis

Micromeritics ASAP 2020

Samples are degassedat temperatures depending on thermal stability

Degassed samples are then analyzed atat 273K and 298K using CO2 as adsorbate gas

Analysis of CO2 capture shows amount adsorbed as a function of pressure (0 to 1 bar)

CO2 adsorption isotherms of stilbenelanthanide MOF

0.18

0.16

0.14

0.12

0.10

0.08

0.06

0.04

0.02

0.00

Amou

nt A

dsor

bed

(mm

ol/g

)

Ln-SDC-AS-273 K Ln-SDC-AS-298 K

0.0 0.2 0.4 0.6 0.8 1.0Relative Pressure (P/Po)28

0.04

0.02

0.06

0.14

0.12

0.10

0.08

Amou

ntAd

sorb

ed(m

mol

/g)

Ln-SDC-H2O-273 KLn-SDC-H2O-298 K

0.000.0 0.2 0.4 0.6 0.8 1.0

Relative Pressure (P/Po)

29

CO2 adsorption isotherms of s t i lbene lanthanide stilbene MOF soaked in H2O

HO O

OHO

NH2

H2N

Contains amine functional groups Open and accessible frameworkCO2 adsorption studies ongoing

+ Ln3+

Amino-stilbene Lanthanide MOFs

17

HO O

OHO

NH2

H2N

+ Cd2+

18

Amino-stilbene based transition metal MOFs

Layered structure bridged via H-bonding and metal-O/N coordinationExploring different synthesis conditions

19

Mixed Ligand Hafnium MOFHO O

OHO

NO2

O2N

O

OHO

OHVery low density MOF ~0.73 g/cm3

Average Hf-O bond length is 2.1 A

Hf(IV)+ +

20

Inner core Hf6-cluster with strong Hf-O bond key to

stability

Hf-coordinated carboxylates

Mixed Ligand Hafnium MOF

21

Very low density MOF ~0.73 g/cm3

Average Hf-O bond length is 2.1 A

Thermally and structural stable when soaked in acetone for 12 h

Mixed Ligand Hafnium MOF

Space filling model

22

Powder x-ray diffraction and TGA of fresh and solvent exchanged Hafnium MOF

Thermograms of fresh and solvent exchanged HfMOFSolvent exchange show more thermally stable material

Powder X-ray diffraction patterns show no change in structure!

0 200 400 600 800 1000

40

60

80

100

Wei

ght %

Temperature (C)

HfMOF HfMOFacetone

0 5 10 15 20 25 30 35 40 45 50 550

210

420

630

8400

300

600

900

Cou

nts

2 Theta

HfMOF

HfMOFacetone

23

CO2 adsorption isotherm of HfMOF

24

HfMOF

CO2 adsorption isotherm at 25 degrees C showing increasing CO2 adsorption as a function of pressure

CO2 adsorption up to 0.7 mmol/g

N

N

OH

O

OH

O

Pyrazine based MOFs

Metals usedGd3+, Eu2+, Mn2+, Zn2+ Ca2+

Metals usedZr(IV) and Hf(IV)

25

+Gd/or Tb

Open framework Large channels ~ 12Å

Kinetic diameter CO2 3.3Å

Channels contain non-coordinating water

{[Gd4(C8N2O8)3(H2O)11]10H20}n

26Ingram et al. Crystengcommun 2015

0.18

0.16

0.14

0.12

0.10

0.08

0.06

0.04

0.02

0.00Amou

nt A

dsor

bed

(mm

ol/g

)

Ln-SDC-AS-273 K Ln-SDC-AS-298 K

0.0 0.2 0.4 0.6 0.8 1.0

Relative Pressure (P/Po)28

Gd-PZTC as synthesized

0.0 0.2 1.0

0.2

0.4

0.6

0.8

1.0Am

ount

adso

rbed

(mm

ol/g

)

0.4 0.6 0.8

Relative pressure (P/Po)

Ln-PZTCA273 K LnPTCA298 K

Gd-PZTC after solvent exchange with chloroform

+Zn2+

29Golafale, Ingram et al. submitted 2017

Calcium pyrazine MOF

+ Ca2+

Golafale, Ingram et al. submitted 2017

+Mn2+

Golafale, Ingram et al. submitted 2017

Zirconium Pyrazine MOF

0 10 20 30 40 50

0

10000

20000

30000

40000

50000

60000

70000

80000

90000

100000

Inte

nsity

(cts

)

2 Theta

Zrpzdc-S4 Zrpzdc-S3 Zrpzdc-S2 Zrpzdc-S1 Zrpzdc-S0

S0 to S4 represent increasing volume of acetic acid added

S0 = no acetic acid added

N

N

OH

O

OH

O

+ Zn(IV)Powder X-ray diffraction

Microcrystalline powder

32

Acetic acid has been used as additive to enhance crystallinity of Zirconium MOF

CO2 adsorption isotherms of Zrpzdc

CO2 Adsorption isotherm at 0 degrees C

0.0 0.2 0.4 0.6 0.8 1.00.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

Qua

ntity

Ads

orbe

d (m

mol

/g)

P/Po

Zrpzdc273K

0.0 0.2 0.4 0.6 0.8 1.0

0.05

0.10

0.15

0.20

0.25

0.30

0.35

0.40 Zrpzdc298K

Qua

ntity

Ads

orbe

d (m

mol

/g)

P/Po

33

CO2 Adsorption isotherm at 25 degrees C

Langmuir Transform model

60 80 100 120 140 160 180 200 220

300

350

400

450

500

550

P/Q

(mm

Hg.

g/m

mol

)

Pressure (mmHg)

Raw data Zrpzdc273K Linear fit

Langmuir Equation P/Q=1/qm*b+P/qPlot P/Q v PIntercept 183.03975 ± 7.3Slope 1.8457 ± 0.0515R-Square 0.99611

60 80 100 120 140 160 180 200 220

700

750

800

850

900

950

1000

Raw data Zrpzdc298K Linear fit

P/Q

(mm

Hg·

g/m

mol

)Pressure (mmHg)

Langmuir Equation P/Q=1/qm*b+P/qmPlot P/Q v PIntercept 584.8749 ± 13.026Slope 1.99026 ± 0.0939R-Square 0.98679

34

𝑷𝑷𝑸𝑸

= ⁄𝟏𝟏 𝒒𝒒𝒎𝒎 ∗ 𝒃𝒃 + ⁄𝑷𝑷 𝒒𝒒𝒎𝒎 𝑺𝑺𝑺𝑺𝑺𝑺𝑺𝑺𝑺𝑺 =𝟏𝟏𝒒𝒒𝒎𝒎 𝑰𝑰𝑰𝑰𝑰𝑰𝑺𝑺𝑰𝑰𝑰𝑰𝑺𝑺𝑺𝑺𝑰𝑰 =

𝟏𝟏𝒒𝒒𝒎𝒎 ∗ 𝒃𝒃

@ 𝟐𝟐𝟐𝟐 𝒅𝒅𝑺𝑺𝒅𝒅𝑰𝑰𝑺𝑺𝑺𝑺𝒅𝒅 𝑪𝑪,𝒒𝒒𝒎𝒎 = 𝟎𝟎.𝟐𝟐𝟎𝟎𝟐𝟐𝒎𝒎𝒎𝒎𝑺𝑺𝑺𝑺𝒅𝒅

; @ 𝟎𝟎 𝒅𝒅𝑺𝑺𝒅𝒅𝑰𝑰𝑺𝑺𝑺𝑺 𝑪𝑪 𝒒𝒒𝒎𝒎 = 𝟎𝟎.𝟐𝟐𝟓𝟓𝟐𝟐𝒎𝒎𝒎𝒎𝑺𝑺𝑺𝑺𝒅𝒅

Adsorption models to be used

35

@ 𝟐𝟐𝟐𝟐 𝒅𝒅𝑺𝑺𝒅𝒅𝑰𝑰𝑺𝑺𝑺𝑺𝒅𝒅 𝑪𝑪,𝒒𝒒𝒎𝒎 = 𝟎𝟎.𝟐𝟐𝟎𝟎𝟐𝟐𝒎𝒎𝒎𝒎𝑺𝑺𝑺𝑺𝒅𝒅

; @ 𝟎𝟎 𝒅𝒅𝑺𝑺𝒅𝒅𝑰𝑰𝑺𝑺𝑺𝑺 𝑪𝑪 𝒒𝒒𝒎𝒎 = 𝟎𝟎.𝟐𝟐𝟓𝟓𝟐𝟐𝒎𝒎𝒎𝒎𝑺𝑺𝑺𝑺𝒅𝒅

@ 𝟎𝟎 𝒅𝒅𝑺𝑺𝒅𝒅𝑰𝑰𝑺𝑺𝑺𝑺 𝑪𝑪,𝒃𝒃 = 𝟎𝟎.𝟎𝟎𝟏𝟏𝟎𝟎𝟏𝟏@ 𝟐𝟐𝟐𝟐 𝒅𝒅𝑺𝑺𝒅𝒅𝑰𝑰𝑺𝑺𝑺𝑺𝒅𝒅 𝑪𝑪,𝒃𝒃 = 𝟎𝟎.𝟎𝟎𝟎𝟎𝟎𝟎𝟓𝟓

Langmuir constant

Finally, we can use the Langmuir constants and the temperatures at 0 and 25 degrees to determine the

thermodynamics of adsorption

Gibbs free energy (G), enthalpy (H), and entropy (S)

Quantity adsorbed

Summary

36

• Synthesized MOFs with metals in accessible sites for CO2adsorption but no CO2 capacity

• Synthesized nitrogen functionalized non-interpenetrating MOFs structure showing promising CO2 capacity

US Department of Energy, National EnergyTechnology Laboratory

DOE Contract FE0022952

Chemistry Department, Clark Atlanta University

Dr. Conrad W. Ingram (PI)

Dr. Tandabany C. Dinadayalane (Co-PI)

Taylor Sledge (Undergraduate)

Kennedi Trice (Undergraduate)