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INSTITUT FRANÇAIS DU PÉTROLE

"Ionic liquids in catalysis: some examples of developments"

Merck Ionic Liquids WorkshopMerck Ionic Liquids Workshop 11th October, 2005

Lyon, France

Christophe VALLÉE, Hélène OLIVIER-BOURBIGOUDepartment of Molecular Catalysis

IFP-Lyon

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• From an industrial point of view, the best solvent is NO solvent

– solvent separation and recycling : energy demanding– possible contamination of the the reaction products– pressure for cleaner technologies....

• Why a solvent ?

– solubilization and stabilization of the active species– enhancement of reaction rates and selectivities– recycling of the catalyst

• biphasic reaction or • monophasic reaction and two-phase separation

• Which solvents ?

The solvent in catalytic reactions

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Ionic liquids in catalysis : advantages

• Ionic liquids do not evaporate !– Containment is much easier than for volatile organic solvents.

• Large set of physico-chemical properties– adjustable miscibility with organic substrates (multiphasic catalysis)– tuneable solvation properties

• Liquid and suitable support for homogeneous catalysts– homogeneous catalyst immobilisation and recovery

• Ionic liquids can interact with solutes and catalytic intermediates– new solvent effect (IL=solvent): new or improved selectivity – promoter for the reaction (IL=“co”-catalyst) : higher activity – stabilization of active species (IL=ligand source) : longer catalyst lifetime

• Improvement of chemical processes– More efficient use of chemicals and catalysts; less waste.– Energy saving.

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– Ni-catalyzed butene dimerisation

– Selective propene dimerisation

– Ni-catalyzed butadiene hydrocyanation

– Co olefin hydroformylation

• Some examples of recent developments in homogeneous catalysis

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Ni-catalyzed Olefin Dimerization

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The Industrial Dimersol IFP Process

First industrial application in 1980 (Japan)...

+ +

Ni(II) + EtAlCl2liquid phase, no solvent

2

200 000t/yr octenesraw material for alcohol synthesis used in plasticizer

manufacturing

6%59%34%

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– Advantages: • mild reaction conditions (40-45°C)• process flexibility

– Limitations:

• Olefin conversion dependent on its concentration

• Dimer selectivity dependent on monomer conversion• Catalyst is neutralised at the output of the reactor although still active

– use of the catalyst is not optimum– continuous catalyst carry over and waste production

The Industrial Dimersol IFP Process

First industrial application in 1980 (Japan)...

+ +

Ni(II) + EtAlCl2liquid phase, no solvent

2

200 000t/yr octenesraw material for alcohol synthesis used in plasticizer

manufacturing

6%59%34%

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The Homogeneous Industrial Dimersol Process

+ +

Ni(II) + EtAlCl2liquid phase, no solvent

2

200 000t/an octenesraw material for alcohol synthesis used in plasticizer

manufacture

6%59%34%

homogeneous catalyst : how to get rid of its limitations ?

NiX2 + EtAlCl2 [olefinNi-Et]+ [AlX2Cl2]-olefin

[olefinNi-H]+ [AlX2Cl2]-

ionic active species

generated in-situ by reaction of Ni(II)

salt + alkylaluminium derivative

Liquid-liquid biphasic catalysis

Which solvent ?

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The choice of the ionic liquid : the organochloroaluminates

NiCl2 + « Et2Al2Cl5 » [LNiEt]+[EtAlCl3]

- + AlCl4-

active speciesthe chloroaluminate IL acts both as solvent and Ni-activator

Acidic Ionic Liquid

ACTIVITY for olefin dimerization in presence of NiX2

Cl-/Al (molar) <1

Et2Al2Cl5-

EtAlCl2EtAlCl3-

Et3Al3Cl7-

Basic Ionic Liquid

Formation of NiCl42-

NON-ACTIVE

Cl-/Al (molar) >1

EtAlCl3-

Cl-

NiCl2

1-Butyl-3-Methylimidazolium chloride + EtAlCl2

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Olefin dimerisation in ionic liquid

Laboratory test

Y. Chauvin, B. Gilbert, I. Guibard, J. Chem. Soc. Chem. Commun. 1715 (1990)Y. Chauvin, S. Einloft, H. Olivier, Ind. Eng. Chem. Res. 34 (4), 1149 (1995)

ionic liquid + Ni

pressure reducer

butene gaz

reaction start-up with stirring

liquid butene

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Olefin dimerisation in ionic liquid

Laboratory test

reaction evolution : formation of a liquid phase not miscible in the IL

magnetic stirring

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Olefin dimerisation in ionic liquid

Laboratory test

decantation of the two phases

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Olefin dimerisation in ionic liquid

Laboratory test

separation of the product phase

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Olefin dimerisation in ionic liquid

Laboratory test

separation of the product phase

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Olefin dimerisation in ionic liquid

Laboratory test

T°C

reaction starts again with the same ionic liquid containing Ni-catalyst

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0

100

200

300

400

500

600

700

0 100 200 300 400 500 600

Temps (min)

Pro

pylè

ne c

on

vert

i (g

)

EtAlCl2:BMIC (1,2:1) molten salts

EtAlCl2:AlCl3:BMIC (0,26:1,2:1)

BMIC + EtAlCl2 (1:1,2)

Dimerization of propene with Ni(II) : lab results

rapid deactivation

2[HNiL]+[EtAlCl3]- 2 « NiHClL » + Et2Al2Cl4

inactif

extrait dans la phase organique

Y. Chauvin, B. Gilbert, I. Guibard, J. Chem. Soc. Chem. Commun. 1715 (1990)Y. Chauvin, S. Einloft, H. Olivier, Ind. Eng. Chem. Res. 34 (4), 1149 (1995)

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0

100

200

300

400

500

600

700

0 100 200 300 400 500 600

Temps (min)

Pro

pylè

ne c

on

vert

i (g

)

EtAlCl2:BMIC (1,2:1) molten salts

EtAlCl2:AlCl3:BMIC (0,26:1,2:1)

BMIC + EtAlCl2

BMIC + AlCl3 + EtAlCl2

Dimerization of propene with Ni(II)

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- representative butene feedstock, no fresh IL added

- run was deliberately stopped after more than 5 months

operation

- IL lifetime and long term stability was demonstrated

Products

Butenes Active phase

containing catalyst

Reactant

Products

Ni

Continuous Flow Pilot Plant Demonstration

F. Favre, A. Forestière, F. Hugues, H. Olivier-Bourbigou, J.A. Chodorge, Oil Gaz European

Magazine, 83, 2/2005

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Benefits of biphasic dimerizationOctene selectivity

70

80

90

100

50 60 70 80 90 100

Butene conversion (%)

Oct

enes

sel

ectiv

ity (%

)

Dimersol (3 reactors)

industrial results

Difasol (pilot results)

Feed : 75% butenes, isobutene<2%

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butenes

butenes octenes

octenes

[Ni]

organic phase

ionic liquid :

very low octene solubility

dodecenes C12

C4

consecutive side-reactions are minimized

Benefits of biphasic dimerization

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Dimersol Difasol Benefits Difasol

Octeneproduction

9.9 t/h 10.2 t/h increased

Relative Niconsumption

1 0.16 reduced

Reactor size 4*120 m3 50 m3 reduced

Benefits of biphasic dimerization

Feed : C4 Raffinate-2, 75% butenes, 20 tons per hour

decrease catalyst consumption decrease reactor volume

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Synthesis of Dimethylbutenes

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Dimethylbutenes : key intermediates for fine chemicals

CH2=CH-CH3 CH2=C-CH-CH3

CH3

CH3

CH3-C=C-CH3

CH3

CH3

DMB-1 DMB-2

O

/t-BuCl AlCl3

CH3COCl AlCl3

CH3

CH3

CH3

CH3

CO2CHCN

OH

insecticideDanitol TM

(by Sumitomo)

musk perfumeTonalid TM

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Industrial production by Sumitomo (1983)

Ni homogeneous catalyst

high 2,3-DMB selectivity (>70%/total hexenes)

elaborate catalyst formula with basic PR3

toluene as solvent

solvent separation needs an efficient distillation column

no catalyst recycling (destruction with NaOH)

The simplest way of DMB synthesis : Selective propene dimerization

+ +2

6% 72% 22%

with no ligand : no regioselectivitywith PR3 ligand : regioselectivity

> 70%

[Ni]

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Propene dimerization in chloroaluminates

Solvent : Acidic chloroaluminate (BMIC : AlCl3 : EtAlCl2)

* after 1 hour reaction time; P(Cy)3 = tricyclohexylphosphine

TOF (Kg/g Ni.h) Dimers (%) 2,3-DMB/C6*(%)NiCl2, Pyridine 6 80-82 7NiCl2, P(Bu)3 8 85-90 32NiCl2, P(iPr)3 12 80-85 83NiCl2, P(Cy)3 8 80-85 83

Phosphine effect

Same Phosphine effect is observed in chloroaluminate as in homogeneous system.

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Competition for the phosphine between «soft » Ni and « hard » AlCl3

[PR3.NiR]+A- + Al2Cl7- [NiR]+A- + AlCl3.PR3 + AlCl4

-

regioselective non regioselective

0

10

20

30

40

50

60

70

80

0 2 4 6 8 10

Time (h)

2,3

-Dim

eth

ylb

ute

nes (w

t%)

NiCl2.2PCy3

Propene dimerization in chloroaluminates

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P N

P-N

0

20

40

60

80

100

0 2 4 6 8 10

Time (h)

2,3-

Dim

eth

ylb

ute

nes

(w

t%)

NiCl2, 2Pi-Pr3

NiCl2, 2P-N

toluene

NiCl2, 2PCy3

aromatic hydrocarbon

Stabilisation of DMB selectivity by addition of small amounts of a weak organic competitive base

[PR3.NiR]+A- + Al2Cl7- + B [PR3.NiR]+A- + AlCl3.B + AlCl4

-

Selective propene dimerization in chloroaluminates

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0

10

20

30

40

50

60

70

80

90

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24

M4P-1

2.3DMB-1

M4P2C

M4P2T

M2P1

H3

H2T

M2P2

H2C

2.3DMB-2

60 hours

DMB-1

Continuous flow propene dimerization in chloroaluminates 2,3-DMB-1 selectivity versus time

• Ionic liquid : 15 mL• propene : atm P • duration : 60 hours• production : 11 liters of products• C6 selectivity : 80-81%/products• 2,3-DMB-1 selectivity : 70-80%/C6

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oligomerizationC2---> C4-C6C3---> C6C4 ---> C8C5---> C10

acid catalysisR+ R

+

IL

[RNi]+A-

Al2Cl7-

H+

Examples of applications of ionic liquids

in chloroaluminates

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[RNi][RNi]++AA--

hydrocyanation

oligomerisationC2---> C4-C6C3---> C6C4 ---> C8C5---> C10

acid catalysisR+ R

+

ILAl2Cl7

-

H+

Ni

Examples of applications of ionic liquids

in chloroaluminates

hydroformylation

selectivehydrogenation

IL

[H2RhL2]+A-

HRh(CO) L3

R R

CHO

R CHO+

in non-chloroaluminates

PF6-, BF4

- , CF3SO3-,

(CF3SO2)2 N- ...

HCo(CO)3L

metathesis of functional olefins

R2

R1

2R1

R1

R2

R2

+

Ru

HCNNC

CN

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Ni-catalyzed Butadiene Hydrocyanation

LCOMS

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CNCN

2M3BN 3PN

NCCN

HCNNi(0)

Phosphite

HCNNi(0)

PhosphiteLewis acid

Ni(0)Phosphite

Adiponitrile

Nylon 6 and Nylon 6,6

Hydrocyanation of butadiene into adiponitrile

Industrial catalyst:

homogeneous nickel(0)-phosphite complexes

LCOMS

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CNCN

2M3BN 3PN

NCCN

HCNNi(0)

P ligand

HCNNi(0)

P ligandLewis Acid

Ni(0)P ligand

Adiponitrile

Hydrocyanation

LCOMS

Model Reaction

Catalytic system: Ni(cod)2 + PPh3 + substrate + ionic liquid

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Hydrocyanation

LCOMS

Selection of the ionic liquid

Conversion as a function of the ionic liquid

0

20

40

60

80

100

BF4

CF3

SO

3

PF6

TF2N

BF4

CF3

SO

3

PF6

TF2N

Non

e io

nic

liqui

d

Con

vers

ion

(in %

)

NN

H

Bu Me

[BMI]

NN

Me

Bu Me

[BMMI]

Catalytic system: Ni(cod)2 + PPh3 + substrate + ionic liquid

C. Vallée et al. / Journal of Molecular Catalysis A: Chemical 214 (2004) 71–81

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Hydrocyanation

LCOMS

NiL4

CNNC

NiL3

CNNiL2

NC

NiL2

NiL2CN

-L +L

LL

charge free active species

need to design special ligands to anchor the catalyst in the

ionic phase

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Hydrocyanation

LCOMS

A wide range of ionic phosphorus ligands

O

P

O

O NN

BF4-

O

N

N

P

TF2N-

3

Ph2P

SO2Na

Ph2P

SO3Na

Ph2PO SO2Na

Ph2P N N

PF6-

N

NPPh2

Et

Me

BF4-

PhP

HN

NH2

NMe2

Br-

2

PHOSPHINES

PHOSPHITES

Advanced Synthesis and Catalysis (2005) accepted

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Hydrocyanation

LCOMS

No trace of nickel or phosphorus(detection limit = 5 ppm)

Recycling experiments

0

20

40

60

80

100

Cycle 1 Cycle 2 Cycle 3 Cycle 4 Cycle 5

TO

N

Ph2P

SO3Na

+ Ni(cod)2 + substrate + [BMMIM][NTf2]

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Co-catalyzed Olefin Hydroformylation

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1st GENERATION

H Co (CO)4

200 -300 bar

150 - 180 °C

Homogeneous catalysis

Basic or acidicextraction of Co

BASF, EXXON.

SHELL (PBu3).

2nd GENERATION

H Rh (CO) (PR3)3

<50 bar

<120 °C

Homogeneous catalysis

Distillation

UCC

Celanese Corp.

3rd GENERATION

H Rh (CO) (TPPTS)3

50 bar

120 °C

Biphasichomogeneous catalysis

Decantation

Ruhrchemie /

Rhône-Poulenc.Olefins C4Olefins C4 PropenePropene

R1 R3

CHO

R4

R5 CHO

H2 / CO

catalyst

branched linear

R2

Olefin hydroformylation: industrial processes

Biphasic catalysis

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H2

O

O

O

O

O

OR

OR

+ double bond position isomers

HydroformylationHydrogenation

CO/H2

Isononanols

Di-isononylPhtalates

water

Dimérisation(Dimersol X)

Olefin hydroformylation

the challenge :

to develop an efficient process

to hydroformylate higher (internal) olefins

with an efficient and simple catalyst recovery

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Olefin hydroformylation : why ionic liquids ?

better solubility of olefins in IL than in water

0,01

0,1

1

10

100

1000

5 6 7 8 9 10 11

Carbon length of alpha olefin

Solubility of olefins in mmol/l

octene-1

hexene-1

decene-1

BMI-BF4

water

-BF4

-NO3

-PF6-SO3-CF3

-CF3COO-N(SO2-CF3)2

0

1

2

3

4

5

6wt % 1-hexene/IL

N N+

N N+ N+ N N+

tuneable solubility of olefins in IL

partial co-miscibility of ionic liquids and reaction products loss of ionic liquid (and catalyst) in the products

F. Favre, H. Olivier-Bourbigou, D. Commereuc, L. Saussine, Chem. Commun. 1360, (2001)

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Co2(CO)8 2 HCo(CO)4 active cobalt catalyst : neutral

H2/CO

- Nature of the active species :

- In presence of an organic base, formation of ionic species

2 ([Co(base)6]2+[Co(CO)4]-2) 6 ([baseH]+[Co(CO)4]-)

2 ([Co(base)6]2+[Co(CO)4]-2) + 8 CO3 Co2(CO)8 + 12 bases

these ionic species have a good affinity for ionic liquids

Olefin Hydroformylation : cobalt catalyst

H2/CO

- base

H2/CO

- base6 HCo(CO)4

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CO/H2

Cobalt catalyzed Hydroformylation of olefins

CO/H 2

Reaction

Produits

Ionic Liquid+ cobalt

P(CO/H2)

CO/H2 CO/H 2

Cobalt Recovery Separation

HCo(CO)4 [Co(base)x ]2+ 2[Co(CO)4

[baseH]+[Co(CO)4]-

+ base

[Co(base)6]+[Co(CO)4]2-

CO/H2

olefins

possible

addition

of

Co2(CO)8

+ base

T and

ionic liquid recycle

the base may help in the generation of the active Co catalyst simple cobalt recovery no by-product generation

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Cobalt catalyzed 1-hexene hydroformylation : results

0

10

20

30

40

50

60

70

80

Run 0

Run 1

Run 2

Run 3

Run 4

0%

20%

40%

60%

80%

100%

Run 0 Run 1 Run 2 Run 3 Run 4

Sel. Lourds

Sel. nd.

Sel. Isom.

Sel. Hydro.

Sel. ol.

Sel. Ald.

- conversion : > 98%- aldehyde selectivity : 75-82 %- recycling of Co « relatively simple »- no need of specially design ligand

SC

F

F F

O

OS C

F

FF

O

NO

-

[N(Tf)2]-

N

N

Me

Bu

+

[BMI]+

mol

H1=

/ m

ol C

o / h

N

- ligand : L/Co=2

- ionic liquid : 6 mL

- substrate : hexene-1 : 15 mL- (co-solvent) heptane : 30 mL

T = 130°C, P = 100bars

Co

nve

rsio

n

Se

lect

ivity

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• Industrial applications:– Some processes using IL have already been industrialized – Ionic liquids are now commercialised and available on ton scale

• Better knowledge of their physico-chemical properties

• A lot of references : more than 20 chemical reactions have been investigated using ionic liquids ...

– Reviews/books :• Multiphasic Homogeneous Catalysis, Wiley-VCH, Weinheim, 2005

• T. Welton, Coord. Chem. Rev. 2004, 248, 2459.• P. Wasserscheid, T. Welton, Ionic Liquids in Synthesis, Wiley-VCH, Weinheim 2003. • H. Olivier-Bourbigou, L. Magna, J Mol. Catal. A: Chemical, 2002, 182-183, 419.• A. H. Azizov, Process of Petrochemistry and oil refining, 2002, 8, 1.• J. Dupont, R. F. de Souza, P. A. Z. Suarez, Chem. Rev., 2002, 102, 3667.

• C. M. Gordon, Appl. Catal. A: General, 2001, 222, 1-2, 101.• R. Sheldon, Chem. Commun., 2001, 23, 2399.

Ionic Liquids in Catalysis

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• Ionic liquids probably cannot be used with benefits in all catalytic processes

• For some specific reactions, they present significant advantages

– they can contribute in improving reaction yield and selectivity

– they can stabilize the catalyst

– the separation of the catalyst (and the solvent) and their recycling can be simplified

– the reactor volume can be lowered

Concluding remarks