Metal-Organic Frameworks and Porous Polymer Networks for Carbon Capture

Carbon Capture Workshop, Tuesday, April 3 rd, Texas A&M, Qatar Metal-Organic Frameworks and Porous Polymer Networks for Carbon Capture J. P. Sculley, J.-R. Li, J. Park, W. Lu, and H.-C. Zhou Texas A&M University

Contents 1. Introduction 2. From MOPs to MOFs 3. MOFs for CO 2 Storage/Separation 4. SRMOFs for Gas Separation 5. PPNs for CO 2 Separation MOPs = Metal-Organic Polyhedra MOFs = Metal-Organic Frameworks SRMOFs = Stimuli-Responsive MOFs PPNs = Porous Polymer Networks

Designing Metal Nodes and Organic Linkers in Synthesis MOPs construction MOFs construction

Applications of MOPs and MOFs Gas Storage CO 2 Capture Separation Catalysis Drug Delivery

Post-Combustion CO 2 Capture 1.0 ton Coal ~ 2.5 tons CO 2 Flue Gas 12% CO 2 74% N 2 12% H 2 O 4% O 2 STEAM Emission Control SO 2, NO x, Hg, Particulate WATER CO 2 Capture Coal* 50% C 20% H 2 O 12% O 2 5% Ash 3% H 2 (S, Hg) Air 78% N 2 21% O 2 *Coal composition varies greatly with grade and source. Purified CO 2 to Storage Regeneration

MOFs for Carbon Capture and Storage How do we selectively sequester CO 2 in high-uptake materials that are low cost, nontoxic, and water stable? (1) increasing CO 2 uptake by generation of MOFs with even higher surface areas and larger pore volumes by the use of larger bridging ligands or highly connected secondary building units (SBUs) (1) increasing the selectivity of MOFs through enhancement of the adsorption enthalpies for CO 2 through decoration of the materials The small kinetic diameter of CO 2 (3.3 Å) High quadrupole moment of CO 2

Bridging-angle modulated MOPs Various polyhedra Metal nodes (Cu, Ru, Mo, Zn, Rh, ) Designed organic ligands with prefixed bridging geometry Assemblies of various angular linkers with a square four-connected node

The Mo 2 (O 2 C ) 4 cluster and dicarboxylate linkers with different bridging angles, sizes, and non-bridging functional groups.

Metal-Organic Cuboctahedra JACS, 2010, 123, 17599.

Metal-Organic Octahedra JACS, 2010, 123, 17599.

Bridging-ligand substitution Synthetic strategy based on the substitution of bridging ligands in soluble MOPs The introduction of linkers with different properties from those of the initial MOP can thus lead to new MOP with distinct properties Partial substitution can also occur and form mixed-ligand species Nature Chem., 2010, 2, 893.

Selective Gas Adsorption of MOPs 80 V ads (cm 3 /g, STP) 60 40 20 77 K N 2 ads H 2 ads 0 0 100 200 300 400 500 600 700 P /mmhg Activated sample (MOP-1) 80 70 V ads (cm 3 /g, STP) 60 50 40 30 20 195 K CO 2 CH 4 10 amorphous 0 0 100 200 300 400 500 600 700 P /mmhg Nature Chem., 2010, 2, 893.

Thermosensitive, Molecular-Sieving Effect Low Temperature Medium Temperature High Temperature Chem. Commun., 2010, 46, 7352.

Stepwise Synthesis of MOP-based MOFs JACS, 2009, 131, 6368.

One-pot Synthesis of MOP-based MOFs PCN-6X Stabilization of Metal-Organic Frameworks with High Surface Areas by the Incorporation of Mesocavities with Microwindows JACS, 2009, 131, 9186.

MOFs with Higher Surface Areas and Larger Pore Volumes Material BET area (m 2 /g) CO2 uptake at 35 bar and 298 K (mmol/g) PCN-61 3350 23.5 PCN-66 4000 26.3 PCN-68 5109 30.4 The surface area of the activated MOF has been increased remarkably by ligand extension, presumably due to the increased size of the mesocavities PCN-61 PCN-66 PCN-68 Angew. Chem. Int. Ed. 2010, 49, 5357 5361.

CO 2 Uptakes of PCN-6X At 35 bar and room temperature, a container filled with PCN-61 can store 8.2 times the amount of CO 2 in an empty container This volumetric capacity is 7.3 for PCN-66 and 7.4 for PCN-68 PCN-6X series are good sorbents for carbon dioxide 19

CO 2 Loading and CO 2 /N 2 Selectivity based on Breakthrough Measurement 1 C/C o q yqtp y VP RT RT f f t s f T b b s m c b (1 ) T b b p t t 0 t b 1 c c o t c dt CO 2 / Time N 2 q CO q N 2 2 y y CO N 2 2 The packed bed porosity b The particle porosity y f The mole fraction of CO2 Q The volumetric feed flow rate t f t The stoichiometric time T Vb p The total porosity The volume of the bed J. A. Ritter et al., Proceedings of the 2002 ASEE Annual Conference

Results of Breakthrough Measurements - Simulated PCN-61 flue Breakthrough gas: 10% curve CO 2 & 90% N 2 - RT, PCN-66 1.0 0.8 C/Co 0.6 0.4 Carbon dioxide Nitrogen 0.2 0.0 0 1 2 3 4 Time (min) q CO2 = 0.24 mmol/g q N2 = 0.14 mmol/g S = 15.4

Why Stimuli-Responsive MOFs? Metal-organic frameworks better than conventional sorbents: possible to design/engineer Stimuli-responsive MOFs based on adjustable kinetics that are not available with other framework materials such as zeolites Molecular gates D(T) S. Ma, et al., ACIE 2007 & JACS 2009 Energy N 2 N 2 * Adsorption CO 2 CO 2 * Reaction Coordinate Stimuli (T, h, ) Energy N 2 N 2 * CO 2 CO 2 * Reaction Coordinate Reverse Stimuli (T, h, ) Desorption Energy CO 2 CO 2 * Reaction Coordinate

Mesh Adjustable Molecular Sieves (MAMS) 24 When the size disparity of the two gases that need to be separated is very small, a molecule sieve with the precise mesh size is not always readily available. In such cases, a meshadjustable molecular sieve (MAMS) that can always meet the separation needs is highly desirable The strategy for the assembly of a MAMS is to construct graphitic MOFs using amphiphilic ligands and metal nodes. In these structures, the gate opening can be tuned by changing temperature (type A) or pressure (type B) Schematic representation of two types of MAMS Metal-containing node and organic linker for the construction of MAMS Structural units in MOF based MAMS with dicarboxylate ligands and Cu 2 paddlewheel units

Temperature Responsive in MAMS-1 25 Zhou et al. Angew. Chem., Int. Ed. 2007, 46, 2458.

Stimuli Responsive Functional Groups 300~400 nm Length : 9.0 Å 5.5 Å π π* transition Kumar, G. S. Chem.Rev. l989, 89, 1915. n π* transition UV Vis or 26

Optically Sensitive MOFs UV Heat trans vs. cis Accessible pore size, surface area, and polarity change 27 Considerations Framework size + functional group size

MOF Design and Synthesis DEF + Zn(NO 3 ) 2 85 MOF 5 type crystal 28 J. Am. Chem. Soc. 2012, 134 (1), 99 102.

Photoresponsive CO 2 Adsorption 22.85 cm 3 /g 16.78 cm 3 /g 10.53 cm 3 /g 29

Reversible CO 2 Adsorption 30

Porous Polymer Network (PPN) Disadvantages: Difficult to characterize No Metals Limited synthetic routes Advantages: Covalent bonds High surface area High gravimetric uptake Extremely low density High thermal stability Chemical stability Chem. Mat. 2010, 22, 5964. 32

Comparison of the networks PPN 3 PPN 4 PPN 5 PAF 1 BET (m 2 g 1 ) 4221 6461 4267 5600 SA calc * 6940 6530 5881 6173 Langmuir (m 2 g 1 ) 5263 10063 6764 7100 Pore volume (cm 3 g 1 ) 2.67 3.04 2.60 3.05 *The accessible surface area is calculated from a simple Monte Carlo integration technique where the probe molecule is "rolled" over the framework surface 33

Hydrogen uptake 10.0 9.0 TAMU PPN-4 Excess Concentration (wt.% H) 8.0 7.0 6.0 5.0 4.0 3.0 2.0 Isotherm: 77 K Run 1, Adsorb Run 1, Desorb Run 2, Adsorb Run 2, Desorb Model Fit 95% CI 1.0 0.0 0 10 20 30 40 50 60 70 80 90 100 Pressure (bar) Results from SWRI (Michael Miller and Carol Ellis) 34

Synthesis of PPN 6 and Modification 35

Postsynthetic Modification Network BET SA (m 2 /g) Pore width (Å) Pore Volume (cm 3 /g) PPN 6 4023 13.6 2.44 PPN 6 SO 3 H 1242 7.5.58 PPN 6 SO 3 Li 1170 6.0.52 36

295K CO 2 uptake Network CO 2 uptake (cm 3 /g) CO 2 uptake (mmol/g) CO 2 uptake (wt%) CO 2 uptake (g/kg) Tap density (g/cm 3 ) CO 2 uptake (g/l) PPN 6 27.2 1.33 5.1 54.0.15 8.1 PPN 6 SO 3 H 75.5 3.56 13.1 149.5.35 52.3 PPN 6 SO 3 Li 82.4 3.68 13.5 156.6.51 79.9 37

Isosteric heats of adsorption 38

IAST predicted adsorption selectivities Dr. Rajamani Krishna 39

Conclusions MOFs, MOPs, and PPNs are materials with a bright future The syntheses of MOPs and MOFs can be well controlled MOFs have extraordinary potential in gas storage SRMOFs are excellent for gas separation PPNs has potential for gas storage/separation

41 Acknowledgments