1. Metals
Ceramics
Polymers
Composites
ZrO2
synthesis
Poornaprajna institute of
scientific Research ,
Bangalore
Vijaykumar Marakatti
Sulfated Zirconia as a strong solid acid
catalyst for selected organic
transformations

2. Outline of the talk
 Introduction.
 Synthesis of zirconia supported catalyst.
 Characterization.
 Structure.
 Acidity and super acidic properties of SZ.
 Application of SZ catalyst for organic
transformations.
 Conclusions.

3. Introduction
Most of the industrially catalyzed
process are based on acid catalyst.
 Different types of acid catalysts
1. Heteropolyacids.
2.Amberlyst
3.Nafion-H
4.Clays and Zeolites.
5.Metal oxides.
6. Anion modified metal oxide.(1980)
ex:Sulfated zirconia, tungated zirconia

4. Metal oxide – ZrO2,TiO2,SnO2,Al2O3 etc
Anion - MoO4
-2 ,SO4
-2,WO4
-2 .
 Modification of metal oxide with anion generate
new active acid sites.
Which are different then their individual acid sites.
Combination of different metal oxide with different
anion gives a large no of catalyst with different
distribution of acid sites.

5. Advantages of Anion Modified metal oxide
 Active over wide range of Temperature.
 Resistant to thermal extrusion.
 Low reaction temperature.
 Easy preparation and low cost.
Disadvantages of Anion Modified metal oxide
 Sensitive to Reducing atmosphere.
 Forms acid if Water is present at high
temperature

6. Synthesis
Sulfated zirconia
a. Sol-Gel
H2SO4
Zirconium n- Propoxide
propanol
Drying 120 C
Calcination 650 C
b. Decomposition
Zr(SO4)2
SO4
-2/ZrO2
Journal of catalysis 150, 18-33(1994)

7. C. Precipitation and impregnation method
ZrOCl2 NH4OH
PH - 8
Zr(OH)4
Zr(OH)4
120 C
H2SO4
SO4
-2/ Zr(OH)4
650 C
SO4
-2/ZrO2
Acidity of catalyst depends
 Activation temperature.
 Precursor
zirconium
sulufur
 sulfur content 1N,2N.
 PH
Synthesis
Chemical review 109, 2185-2206(2009)

8. Synthesis
Tungstated zirconia
a. Impregnation method( dry , wet ,incipient)
Ammonium tungatate + H2O
ZrO2 or Zr(OH)4
80 C 2hr
Stir for 4 hr
110 C 6hr
Calcined at 600C
WOX/ZrO2
Evaporation
 Co-precipitation
 Calcinations temperature.
 Preparation method.
Catalysis letters 131, 122-128(2009)

9. Characterization
a. X-Ray Diffractometer
10 20 30 40 50 60 70
ZrO2
SZ 1N
SZ 1.5N
SZ 2N
WO3
/ZrO2
Intensity(a.u)
tt
Present Work
WOX/ZrO2
SZ-2N
SZ-1.5N
SZ-1N
ZrO2

10. b. FT-IR Spectra
Characterization
900 1000 1100 1200 1300 1400
995
1044
1138
1212
%Transmitance
Wavenumber(cm
-1
)
SZ 2N
PRESENT WORK

11. C. TG-DTA
Characterization
575 C
600 C
650 C
B.M Ready .etal Chemical review 109, 2185-2206(2009)

12. d. Textural properties
Characterization
material Surface
area
M2/g
Crystalline
size(nm)
Sulfur / W
loading
ZrO2 42 11.2 --
SO4
-2/ZrO2 100 7.3 2.3
WO3/ZrO2 35 11.9 6
Journal of molecular catalysis A. Chemical 109, 2185-2206(2009)

13. Structure
B.M Ready .etal Chemical review 109, 2185-2206(2009)

14. ACIDITY
material NH3 desorbed
(Ml/gram)
ZrO2 5
SO4
-2/ZrO2 16
WO3/ZrO2 9
(TPD)

15. ACIDITY(FTIR- Pyridine)
Catalyst B/L ratio
SO4
2/ZrO2(1N) 1.6
SO4
2/ZrO2(1.5 N) 1.03
SO4
2/ZrO2(2 N) 0.92
B/L Ratio : SZ 2N<SZ 1.5N< SZ1N.
Present work
1700 1650 1600 1550 1500 1450 1400
ZrO2
SZ-1N
SZ-1.5N
SZ-2N
LB+LB
Absorption(a.u))
wavenumber (cm
-1
)

16. Super acidity?
 Bronstead & lewis acidity.
 Ho indicator method.
 Colour change.
 Different acid sites.
 TPD
 Decomposition of
adsorbate molecule.
 adsorption on catalytically
not active.
 CaO-NH3- at high T
 Skeletal isomerization
at low T.

17. Commercial application in hydroisomerization process
n- Paraffins H2 iso-Paraffin
- Aromatics – high octane number and C/H ratio
- Branched HC – High octane Number
- Hydro cracking is competing reaction.
- Low temperature.
- Bi-functional catalyst.
- Pt/Alumina /Cl-.
- Pt / SiO2-Al2O3.
- Pt /Sulfated zirconia-HYSOPAR-100 ppm
- WO3/ZrO2.
Applications in organic transformations

19. Selective hydrolysis of cellulose into glucose
 Cellulose is the most abundant source of biomass.
 Enzyme catalyst – separation problems.

20. Reaction conditions: milled cellulose 45 mg, catalyst 50 mg, distilled water 5.0
mL, 24 h.

21. Prins Cyclization
O
H H
O
OH+
 Condensation of olefin with aldehyde.
 C-C bond forming reaction.
Styrene Para formaldehyde 4-Phenyl 1,3-Dioxane
 Industrially high boiling solvent.
 Plasticizer, curing agent , Pigment dispersant
 Protecting group in organic synthesis.
 monomer and additives in polymer industry.
U.S Patent -4,185 ,019 Jan.22(1980)

22. Catalyst Formaldehyde source Yield
Sulfuric acid Formaldehyde 75
Heteropolyacids Paraformaldehyde 99
Trifluromethane sulfonic acid Formaldehyde 92
MoO3/SiO2 paraformaldehyde 73
SO3H-SBA-15 Formaldehyde 100
Indium bromide
Ionic liquids
paraformaldehyde 91
Organic salt of heteropolyacids Formaldehyde 97
Zeolites paraformaldehyde 40
Sulfated zirconia paraformaldehyde 93
Literature survey

23. Reaction conditions; 20 mmol styrene, 60 mmol
paraformaldehyde, solvent :dichloroethane =10ml ;
Catalyst: SZ-2N. Temp =80 C. Reaction time: 6hr
Catalyst Time
in hrs
Conversion
Wt%
Selectivity
Wt%
TON
mmol/gram
SO4-2/ZrO2 7 99.8 92 67.66
WO3/ZrO2
7 96 85 60.14
H-Beta(25) 7 22 88 14.14
H-ZSM-5(38) 7 1 30 o.22
H-Y(16) 7 1 50 o.36
H-Mordenite(16) 7 2 46 0.67
Cs2.5H0.5SiW12O40 1 97 68 49.33
Montomorlonite-K-10 2 100 67 49.36
Reaction conditions; 20 mmol styrene, 60 mmol paraformaldehyde, solvent :dichloroethane =10ml ;
Catalyst : 7 wt % of reactant, Temp =80 C. Reaction time: 6hr
Screening of catalyst

24. Effect of solvent
solvent Dielectric
constant
Acceptor
Number(A.N)
Donor
Number (D.N)
Yield for
4-Phenyl
1,3 dioxane
No solvent --- --- --- 56
Tri ethyl amine 2.4 0
Cyclohexane 2.6 47
Toluene 2.4 64
1,2dichloro ethane 10.1 85
Nitrobenzene 34.8 22
Acetonitrile 36 0
Isopropyl alcohol 18.3 33.8 21.1 0
Reaction condition: 10 mmol styrene; 30 mmol Paraformaldehyde; 10 wt% of catalyst (reactant); Temp =80 C;
solvent =5ml; reaction time =7 hr.
The acceptor number( Lewis acidic) is obtained from the 31PNMR chemical shift values related to that of the
1:1 adduct (C2H5)3PO-SbCl5 dissolved in 1,2 dichloroethane.
The Donor number (Lewis base) defines the negative DH value for 1:1-adduct formation between sbCl5 and an
electron pair donor solvent in diluted solution in non coordinating solvent 1, 2-dichloro ethane.
1.4 61
0 0
8.2 0
16.7 0
14.8 4.4
18.9 14.1

25. Catalyst Acidity B/L
ratio
Time in (hr) conversion Selectivity
Blank ---- 7hr 1.6 70
Zr(OH)4 --- 7hr 1.7 72
ZrO2 --- 7hr 2.3 74
SZ-1N 1.6 3hr 87.8 74.6
SZ-1.5N 1.04 3hr 76.3 78
SZ-2N 0.92 3hr 73 88
7hr 99.8 92
Sz-2Na --- 7hr -- --
Sz-2Nb -- 7hr -- --
Reaction conditions; 20 mmol styrene, 60 mmol paraformaldehyde, solvent :dichloroethane =10ml ;
Catalyst: SZ-2N. Temp =80 C. Reaction time: 6hr.
a- Aqueous Formaldehyde instead of paraformaldehyde.
b – Aqueous Formaldehyde instead of paraformaldehyde, reaction temperature = 100 C
Sulfated zirconia catalyst

26. 60 80 100
40
50
60
70
80
90
100
Reaction Temperature
conversionofstyrene
60
70
80
90
100
selectivityofdioxane
Optimization of reaction conditions.
a. Temperature
Reaction conditions; 20 mmol styrene, 60 mmol paraformaldehyde, solvent :dichloroethane
=10ml ;Catalyst: SZ-2N. Temp =80 C. Reaction time: 7hr , catalyst weight -7 wt%.
Reaction time -100C – 4hr

27. 3 5 7 9
60
65
70
75
80
85
90
95
100
Percentage(%)
catalyst (wt%)
conversion of styrene
selectivity for 4 phenyl 1,3 dioxane
b. Catalyst weight
Reaction conditions; 20 mmol styrene, 60 mmol paraformaldehyde, solvent :dichloroethane
=10ml ;Catalyst: SZ-2N. Temp =80 C. Reaction time: 7hr

28. 1:1 1:2 1:3 1:4
0
20
40
60
80
100
Percentage(%)
Styrene:Paraformaldehyde mole ratio
conversion of styrene
selectivity for 4-Phenyl 1,3-dioxane
selectivity for cinnamyl alcohol
C. Mole ratio of styrene :paraformaldehyde
Reaction conditions; solvent :dichloroethane =10ml ;Catalyst: SZ-2N. Temp =80 C. Reaction
time: 7hr , catalyst weight -7 wt%.

29. Leaching test
0 1 2 3 4 5 6 7 8 9 10
0
10
20
30
40
50
60
70
80
90
Percentage(%)
Time (hr)
conversion of styrene
selectivity for 4-Phenyl1,3-dioxane
Reaction condition: 20 mmol styrene: 60 mmol Paraformaldehyde; 7 wt% of
catalyst (reactant); Temp =80 C; solvent: Dichloro ethane =10ml.

30. Recycling test
Catalyst Yield
cycle 1 92
cycle 2 91.4
cycle 3 90
cycle 4 89.8
10 20 30 40 50 60 70
Cycle 4
Cycle 3
Cycle 2
Cycle 1
Intensity(a.u)
2 Theta

31. S
O
O
Mechanism of reaction
C
O
H H
H
OH
H
C
O
H
Zr
O
O
O
O
OH
O
O
CH2OH
O
O
OH
H
S
L
B
ZrO2

32. conclusion
 Sulfated and tungstated zirconia catalyst were
synthesized by the precipitation and impregnation
method.
 Characterization of sulfated zirconia by various
methods were discussed.
 Prins reaction of styrene with Paraformaldehyde
is carried out using Sulfated zirconia catalyst.
 Optimization study , effect of solvent and comparison of
other acid catalyst is done.
 SZ-2N showed good activity and selectivity for the prins
reaction.

33. Thank You