1. Novel Synthesis and Activation strategies leading to the formation of tuned mesostructures

2. Optimal Sorbent and Catalyst support requirements A. High adsorption capacity High number of active sites B. High selectivity: * pore volume * pore size distribution * surface area * surface composition C. Good kinetic properties: selection of * crystal size * particle size * porosity * binder type D. Good physical properties: * high bulk density * crush strenght * erosion resistance E. Good lifetime performance: * high chemical, thermal and mechanical stability

3. Mesoporous Templated Silicas General Introduction Mesoporous Templated Silicas (MTS) MCM- 41 MCM- 48 SBA-15 SBA-16 PORE DIAMETER 2 - 6 nm 6 - 20 nm

4. Typical Laboratory Synthesis Conditions MCM-41 MCM-48 SBA-15 SBA-16 CTMABr Gem 16-8-16 Gem 16-12-16 Pluronic P123 EO 20 PO 70 EO 20 Pluronic P127 EO 106 PO 70 EO 106 13 <1 TEOS/ Fumed silica TEOS/ Fumed silica TEOS 1/ 0.25 1/0.06 1/ 0.1 1/ 0.02 1/ 0.008 TemplatepH Silica source Si/Templ. Synthesis Characteristics 24 h at RT° + 2 days at 130°C in AC + 3 days HT 5 days at 130°C in AC + 3 days HT stirring 8 h at 45°C + ageing 16 h at 80°C stirring 8 h at RT° + ageing 16 h at 80°C Mesoporous Templated Silicas CTMABr: Cetyltrimethylammonium bromide Gemini: [C m H 2m+1 (CH 3 ) 2 N-C s H 2s -N(CH 3 ) 2 C n H 2n+1 ]2Br

5. Structural Characteristics Symmetry Surface Area (m²/g) Pore Volume (ml/g) Wall Thickness (nm) P6m (Hexagonal) 1000 1.2 1 Ia3d (Cubic) 1200 1.2 – 1.5 1 P6mm (2D Hexagonal) 700-1000 0.7 – 1.3 4 – 6 Im3m (Cubic) 700-900 0.4 – 0.8 5 – 8 MCM-41MCM-48SBA-15SBA-16 Mesoporous Templated Silicas

6. Pore Size Engineering of MCM materials The effect of the synthesis conditions Influence of the chain length of the surfactant Addition of co-templates 4 4 4 4 4 4 Tuning pore size distrubution

7. Pore Size Engineering MCM Synthesis Conditions Tuning of the pore size of the MCM material by selecting the synthesis conditions A B C D A = 1 day base +1 day HT * r p = 1.0 nm B = 5 days base + 3 days HT r p = 1.2 nm C = 10 days base + 1 days HT r p = 1.3 nm D = 10 days base + 3 days HT r p = 1.5 nm * HT = Hydrothermal treatment

8. Pore Size Engineering MCM Influence of the chain length Gem 16-12-16 Gem 18-12-18 Physical Properties: Gem 16-12-16 S BET = 1300 m 2 /g V P = 1.0 ml/g r P = 1.2 nm Gem 18-12-18 S BET = 1600 m 2 /g V P = 1.4 ml/g r P = 1.3 nm Synthesis Conditions: 5 days at 130°C followed by hydro- thermal treatment of 3 days at 130°C Difference in surfactant side chain length

9. Pore Size Engineering MCM Addition of Co –Templates 0 0.3 0.6 1 1.2 1.8 Gemini surfactants Dimethylalkyl amines Enlargement of the pore size of MCM-48 due to the addition of dimethyl-hexadecyl amine as a swelling agent with different ratio of amine/surfactant. Other additives can be used like ethanol, decane and different dimethylalkyl amines. Mechanism: Micelle Ratio of surfactant co–template

10. Morphologies of MCM Different morphologies: - fibers - layers - gyroids - rods -spheres - ….

11. Hollow core spheres Hard spheres Morphologies of MCM

12. Cubic core Hexagonal channels Morphologies of MCM

13. Catalytic Activation Overview Methods for catalytic activation in situ activation (during the synthesis) post-synthesis modification (after the synthesis) framework incorporation + surface modifiction surface modification various metal oxides (V, W, Ti, Cr, Mo, Al,…)

14. Catalytic Activation Surface Modification The Molecular Designed Dispersion VO(acac) 2 : Vanadylacetylacetonate

15. Catalytic Activation Spectroscopic Characterization FTIR Spectroscopy Si-OH H-bonding V-OH acac Si-O-V Blank MCM VO(acac) 2 + MCM VO x /MCM

16. Catalytic Activation Spectroscopic Characterization FT-Raman Raman frequency~V-O bond length ~VO x coordination  1042 cm -1 : (V=O) tetrahedral 997 cm -1 : (V=O) octahedral 0.2 mmol/g 1.3 mmol/g 0.7 mmol/g 0.4 mmol/g 1042 cm -1 997 cm -1 v2o5v2o5 S V O O O O S S VO x /MCM catalysts < 1 mmol/g V : tetrahedrally coordinated VO x Raman spectroscopy is very sensitive towards micro-crystalline V 2 O 5

17. 0 2 4 6 8 10 12 14 16 18 200300400500 Wavelength (nm) Kubelka Munk Units Catalytic Activation Spectroscopic Characterization VO x coordinationBand position (nm) tetrahedral isolated250, 300 tetrahedral 1D chains350 square pyramidal410 octahedral470 (a) 0.4 mmol/g V (b) 0.7 mmol/g V (c) 1.3 mmol/g V O  V charge transfer bands ~ VO x coordination Progression of polymerisation as a function of the surface loading : UV-VIS-DRS (a) Isolated tetrahedral (b) isolated + 1D chains (c) isolated + chains + V 2 O 5 crystals

18. Catalytic Activation Catalytic Performance Oxidation of methanol (at T = 400°C) Conversion  CO x  Formaldehyde+ dimethylether Tetrahedral VO x :  activity increases with V loading  high formaldehyde yield Formation of V 2 O 5 clusters :  activity decreases  selectivity decreases drastically

19. Catalytic Activation Catalytic Performance Oxidation of methanol (at T = 400°C) On pure, grafted and incorporated VO x -MCM materials for different vanadium loadings Acidic sites Dimethylether (DME) Basic sites Carbonoxides (CO) Redox sites Formaldehyde (FA)

20. Catalytic Activation Supported Mixed Oxide Catalysts Synthesis of a new mixed oxide phase using the Molecular Designed Dispersion method : Vanadium oxide + Tantalum oxide Combining different oxide phases  Synergy or complementary properties  Improved catalytic performance Structural characterization FTIR, FT-Raman, UV-VIS-DRS Surface properties Adsorption of pyridine Catalytic performance

21. Catalytic Activation Supported Mixed Oxide Catalysts FT-RamanFTIR S V O O O O S S S V O O O O S S S Ta O O O S O S O O O S O S S S V O O O O S S Ta=O V=O Si-O-VTa=O Si-O-Ta Blank VO x TaO x VO x -TaO x Well-mixed and well-dispersed VO x -TaO x catalysts

22. Catalytic Activation Supported Mixed Oxide Catalysts Catalyst with active redox and active acid sites Oxidation of methanol (at T = 250°C) Redox site VO x Acid site TaO x + VO x -TaO x Redox site :formaldehyde, methylformate Acid site :dimethylether Selectivity (%) (0.4 mmol/g) (0.2 mmol/g) (0.4 mmol/g V + 0.2 mmol/g Ta) VOx TaOx VOx-TaOx Formaldehyde Methylformate Dimethylether 0 10 20 30 40 50 60 70 80 90 100

23. SBA-15 and SBA-16 Promising Materials Qualities of SBA materials Relatively large mesopores Large amount of micropores Thick pore walls Incorporation of hetero-elements in thicker walls Higher hydrothermal and mechanical stability Use of non-toxic, biodegradable, non-ionic triblock copolymers as template 

24. SBA-15 and SBA-16 A comparison with MCM-48 SBA-15 SBA-16 MCM-48 5.0 3.0 1.4 1.3 0.6 1.0 900 800 1200 S BET (m³/g) V p (ml/g) r p (nm)

25. Tuning pore size distribution Pore size engineering Changing synthesis conditions 4 size of surfactant 4 use of swellers 4 Synthesis temperature

26. Size of surfactant Length of EO blocks (ethyleneoxide) Characteristic for mesophase (structure) Wall thickness Triblock copolymers (pluronics)(EO) x (PO) y (EO) x EO4 units 17 - 37 units 132 units lamellar hexagonal cubic Length of PO blocks (propyleneoxide) influences porediameter PO 30 units 70 units 3 nm ø 8 nm ø Pore size engineering

27. Addition of swellers (TMB, 1,3,5- trimethylbenzene) Pore enlargement mesocellular foam MCF Pore size engineering

28. In situ control of mesopore radius by changing the synthesis conditions using the same surfactant (EO 70 PO 20 EO 70 ) The SBA-15 materials were aged for 16 h at different temperatures: Sample A = 75°C Sample B = 90°C Sample C = 105°C A part of non calcined sample A had a hydrothermal treatment for 3 days at 100°C (Sample D) A B D C Pore size engineering

29. In situ control of micro/mesopore volume ratio by changing the synthesis conditions using the same surfactant (EO 70 PO 20 EO 70 ) Variable micro/mesopore volume Pore size engineering Sample A: aged for 16h at 75°C Sample D: part of non calcined sample A after a hydrothermal treatment at 100°C for 3 days

30. Morphologies of SBA Fibers of SBA

31. Morphologies of SBA Spherical SBA low µm range high µm range cm range

32. Morphologies of SBA Growth mechanism of spherical SBA

33. Catalytic activity of VOx and TiOx / SBA-15 in SCR of NO with ammonia. DeNOx: 4 NO + 4 NH 3 + O 2 4 N 2 + 6 H 2 O 0 20 40 60 80 100 200300400500 Temperature (°C) Conversion / Selectivity (%) TiO x / SBA-15VO x / SBA-15 0 20 40 60 80 100 200300400500 Temperature (°C) Conversion / Selectivity (%) Not active below 350°CNot higher than 55% of conversion Activation of SBA materials by MDD and Catalytic performance Post-synthesis modification

34. SBA Catalytic performance Mixed oxide TiO x - VO x / SBA-15 catalyst 0 20 40 60 80 100 150200250300350400 Temperature (°C) Conversion / Selectivity (%) VO x - TiOx / SBA-15 Very active in a low temperature range ~100% NO conversion (above 250°C) ~100% N 2 selectivity (all temp. range)

35. Post-synthesis modifications Simultaneous formation and activation metal oxides nanoparticles zeolite based nanoparticles Related SBA materials In situ formation of amorphous siliceous microporous nanoparticles

36. open mesopores ink-bottle mesopores SBA-15 and related materials PHTS Typical N 2 sorption isotherms (77K) for various SBA-15 materials

37. PHTS (Plugged Hexagonal Templated Silica) PHTS V micropores V narrowed meso V meso open

38. Post-synthesis modifications Simultaneous formation and activation metal oxides nanoparticles zeolite based nanoparticles Related SBA materials In situ formation of amorphous siliceous microporous nanoparticles

39. metal oxides nanoparticles (TiO 2 ) Related SBA materials tuneable size tuneable crystal phase (rutile, anatase) tuneable number of active sites tuneable porous characteristics (size, number)

40. Post-synthesis modifications Simultaneous formation and activation metal oxides nanoparticles zeolite based nanoparticles Related SBA materials In situ formation of amorphous siliceous microporous nanoparticles

41. TPAOH 20% TEOS VOSO 4 nanoparticles zeolites (vanadiumsilicalite) ageing 2 days calcined SBA-15 acidification (HCl) SBA-15 with zeolitic plugs inside the mesopores Dry impregnation SBA and related materials Silicalite-1 nanoparticle deposition

42. Open mesopore narrowed mesopore Crystalline vanadiumsilicalite-1 nanoparticle nanoparticles can be: 4zeolitenanoparticles, metaloxides 4microporous, non-porous SBA and related materials Silicalite-1 nanoparticle deposition

43. In situ synthesis strategies Mesoporous materials with zeolite-like walls classic (vanadium) silicalite-1 synthesis mixture: TPAOH, H 2 O and TEOS, (VOSO 4 ) clear solution containing nanoparticles (vanadium) silicalite-1 zeolite hydrothermal treatment acidification: pH<1 silicalite-1-like nanoparticles with modified surfactant hydrothermal treatment NO TEMPLATE mesoporous surfactant and refluxing short range ordered mesoporous material with tuneable porosity and hydrophobicity long range ordered mesoporous materials with ink-bottle pores Mesoporous materials with silicalite-1-like walls

44. In situ synthesis strategies Mesoporous materials with zeolite-like walls classic (vanadium) silicalite-1 synthesis mixture: TPAOH, H 2 O and TEOS, (VOSO 4 ) clear solution containing nanoparticles (vanadium) silicalite-1 zeolite hydrothermal treatment acidification: pH<1 silicalite-1-like nanoparticles with modified surfactant hydrothermal treatment NO TEMPLATE mesoporous surfactant and refluxing short range ordered mesoporous material with tuneable porosity and hydrophobicity long range ordered mesoporous materials with ink-bottle pores Mesoporous materials with silicalite-1-like walls

45. In situ synthesis strategies Mesoporous materials with zeolite-like walls classic (vanadium) silicalite-1 synthesis mixture: TPAOH, H 2 O and TEOS, (VOSO 4 ) clear solution containing nanoparticles (vanadium) silicalite-1 zeolite hydrothermal treatment acidification: pH<1 silicalite-1-like nanoparticles with modified surfactant hydrothermal treatment NO TEMPLATE mesoporous surfactant and refluxing short range ordered mesoporous material with tuneable porosity and hydrophobicity long range ordered mesoporous materials with ink-bottle pores Mesoporous materials with silicalite-1-like walls

46. In situ synthesis strategies Mesoporous materials with zeolite-like walls CH 3 CH 2 a) tripropylamine, b) TPAOH 20% solution, c) the full-grown VS-1 zeolite before calcination, d) SBA-VS-15 with acidified nanoparticles before calcinations EPR and Raman show the loss of a ligand from the silicalite-1 template (TPAOH) Consequences of acidifying the solution of vanadiumsilicalite-1 nanoparticle 14 N EPR HYSCORE spectra of SBA-VS with acidified vanadium silicalite-1 nanoparticles EPR HYSCORE spectra of full-grown vanadium silicalite-1 interaction of 14 N with V

47. In situ synthesis strategies Mesoporous materials with zeolite-like walls Consequences of acidifying the solution of vanadiumsilicalite-1 nanoparticle HT No mesotemplate HCl loss of n-propyl ligand stops the zeolite growth +

48. In situ synthesis strategies Mesoporous materials with zeolite-like walls Consequences of acidifying the solution of vanadiumsilicalite-1 nanoparticle hydrothermal treatment NO TEMPLATE Temp tuneable porosity Time tuneable porosity hydrophobicity low pH growth of mesopores by edge-sharing (resembles sol-gel mechanism)

49. Conclusions “Abracadabra” is a well-known incantation in the magic world, although the synthesis of tuned porous materials may still seem an art to many, it nonetheless can be understood to a certain level, appreciated and successfully performed. Making a white powder is by no means the end of the road in preparing porous materials; it is equally important to be able to characterize or to indentify, to engineer the porosity and to activate these materials that have been prepared for a desired application in sorption, catalysis and membranes.

50. Acknowledgements * INSIDE PORES NoE * University of Antwerpen: Prof. P. Cool Vera Meynen Wesley Stevens Liu Shiquan * I.A. Cuza University, Iasi, Romania: A. Busuioc A. Hanu