1. Solid Bases and Other Materials

2. Molecular Sieves
Small pores of precise and uniform size (could serve as desiccants – silica gel, activated carbon)
Microporous sieves (pore size less than 2 nm (20 Å))
Zeolites (alumosilicate materials)
Porous glass
Active carbon
Clay
Mesoporous sieves (pore diameter between 2 and 50 nm ( Å)
Silicon dioxide, mesoporous silica
Macroporous sieves (pore diameter is greater than 50 nm (500 Å)
TEM (a, b, and c) images of prepared mesoporous silica nanoparticles with mean outer diameter: (a) 20nm, (b) 45nm; and (c) 80nm. SEM (d) image corresponding to (b). The insets are a high magnification of mesoporous silica particle
A.B.D. Nandiyanto; S.-G Kim; F. Iskandar; and K. Okuyama (2009). "Synthesis of Silica Nanoparticles with Nanometer-Size Controllable Mesopores and Outer Diameters". Microporous and Mesoporous Materials 120 (3): 447–453. doi: /j.micromeso

3. Molecular Sieves …
Able to distinguish materials on the basis of their size
May be crystalline, non-crystalline, para-crystalline or pillared clays
Have variable framework charge with porous structure

4. Calcination
thermal treatment process (air or oxygen present) at temperatures below the melting point
Brings about:
thermal decomposition
phase transition
removal of a volatile fraction
Examples
Removal of ammonium ions in the synthesis of zeolites
Removal of carbon dioxide from alkaline earth carbonates

5. Base Catalysis in Organic Synthesis
General Base Catalysis Mechanism
Tischenko Reaction
benzylaldehyde
Benzyl benzoate

6. Commercial Applications of Tischenko Reaction
Ethyl acetate from acetoaldehyde (aluminium alcoholate traditional catalyst)
Isobutyl isobutyrate
- Hydroxypivalic acid neopentyl glycol
- Methyl formate.[6]

7. Other Reactions Involving Base Catalysis
Aldol Reaction – Formation of C-C bond
Aldol – Tischenko Reaction – Formation of 1,3-hydroxyl compounds from aldehydes and ketones

8. Other Reactions Involving Base Catalysis
Meerwein-Ponndorfp-Verley Reduction
Knoevenagel Condensation - nucleophilic addition of activated carbon compound

9. Solid Phase Bases
Potassium fluoride on alumina (KOH, weaker base)
Alkali and alkaline earth carbonates
Hydrotalcites (general formula Mg6Al2CO3(OH)16·4(H2O))
double hydroxide carbonates
Guests:
Carboxylates
Sulfates
Phosphates
Porphyrins
Polyoxometalates
What will happen to a double hydroxide carbonate during calcination?

10. Solid Phase Bases (Cont’s)
Magnesium Oxide
Calcium Oxide
Hydroxyapatite Ca10(PO4)6(OH)2
Superbases: Alumina/Magnesium Oxides + Alkali metal hydroxide + Alkali metal (under N2)

11. Zeolites Aluminosilicates as skeletal composition
How do molecular sieves and zeolites relate to each other?
Aluminosilicates as skeletal composition
Highly crystalline materials
Anionic framework with microporous and crystalline structure
Could be synthetic and natural

13. Zeolites Have Various Frameworks

14. Zeolites Vary By… Silicon-to-Aluminum Ratio Pore diameter Counter ion
Framework

15. Commercial Use of Zeolites
Detergents
Separate linear polymers from branched
Oxygen enrichment
Removal of carbon dioxide, hydrogen sulfide, mercaptans from air
Petroleum cracking
Catalysis

16. Metal Organic Frameworks (MOF)
Organic compounds: polyphenols, difunctional carboxylic acid, sulfonic acid, phosphonic acid, hydroxamic acid, boronic acid, etc...
Metal ions: Zn, Co, Ni, Eu, La, Ce, Er, Lu, Yb, Cr, V, Fe, Zr
Have more open space (60%) than zeolites (50%)
High thermal stability

17. An illustration of a prototype 6-liter adsorbed natural gas (ANG) fuel tank that relies on innovative advanced porous materials and Texas A&M's proven expertise in metal-organic frameworks and porous-polymer networks to deliver low-pressure, high-density natural gas storage in vehicles

18. Clays Al, Fe, Mg silicates
Crystalline inorganic polymers (may be amorphous too)
(Na,Ca)0.33(Al,Mg)2(Si4O10)(OH)2·nH2O - montmorillonite

19. Applications of Clays Replacements for asbestos Molecular sieves
Catalysts
cationic and anionic clays
could substitute for Lewis acids
Offer selectivity by size and shape
Acylation
Alkylation
Rearmaments

20. Montmorilloite and CO2 Sequestration
CO2 intercalation into swelling clay layers is of potential use for CO2 storage in geological formations.
CO2 intercalation into caprock dominated with clay can lead to swelling and eventual evolution of fractures due to geomechanical stress
Also valuable model systems for understanding the structure of water and water/CO2 mixtures in confined environments

21. Myshakin et al., Molecular Dynamics Simulations of Carbon Dioxide Intercalation in Hydrated Na-Montmorillonite, Journal of Physical Chemistry A, 2013, 117 , 11028–11039