1 INSTITUT FRANÇAIS DU PÉTROLE "Ionic liquids in catalysis: some examples of developments" Merck Ionic Liquids Workshop 11th October, 2005 Lyon, France Christophe VALLÉE, Hélène OLIVIER-BOURBIGOU Department of Molecular Catalysis IFP-Lyon

2 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

3 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.

4 –Ni-catalyzed butene dimerisation –Selective propene dimerisation –Ni-catalyzed butadiene hydrocyanation –Co olefin hydroformylation Some examples of recent developments in homogeneous catalysis

5 Ni-catalyzed Olefin Dimerization

6 The Industrial Dimersol IFP Process First industrial application in 1980 (Japan)...

7 –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)...

8 The Homogeneous Industrial Dimersol Process homogeneous catalyst : how to get rid of its limitations ? ionic active species generated in-situ by reaction of Ni(II) salt + alkylaluminium derivative Liquid-liquid biphasic catalysis Which solvent ?

9 The choice of the ionic liquid : the organochloroaluminates Acidic Ionic Liquid  ACTIVITY for olefin dimerization in presence of NiX 2 Cl - /Al (molar) <1 Et 2 Al 2 Cl 5 - EtAlCl 2 EtAlCl 3 - Et 3 Al 3 Cl 7 - Basic Ionic Liquid Formation of NiCl 4 2-  NON-ACTIVE Cl - /Al (molar) >1 EtAlCl 3 - Cl - NiCl 2 1-Butyl-3-Methylimidazolium chloride + EtAlCl 2

10 Olefin dimerisation in ionic liquid Laboratory test Y. Chauvin, B. Gilbert, I. Guibard, J. Chem. Soc. Chem. Commun (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

11 Olefin dimerisation in ionic liquid Laboratory test reaction evolution : formation of a liquid phase not miscible in the IL magnetic stirring

12 Olefin dimerisation in ionic liquid Laboratory test decantation of the two phases

13 Olefin dimerisation in ionic liquid Laboratory test separation of the product phase

14 Olefin dimerisation in ionic liquid Laboratory test separation of the product phase

15 Olefin dimerisation in ionic liquid Laboratory test T°C reaction starts again with the same ionic liquid containing Ni-catalyst

16 BMIC + EtAlCl 2 (1:1,2) Dimerization of propene with Ni(II) : lab results rapid deactivation extrait dans la phase organique Y. Chauvin, B. Gilbert, I. Guibard, J. Chem. Soc. Chem. Commun (1990) Y. Chauvin, S. Einloft, H. Olivier, Ind. Eng. Chem. Res. 34 (4), 1149 (1995)

17 BMIC + EtAlCl 2 BMIC + AlCl 3 + EtAlCl 2 Dimerization of propene with Ni(II)

18 - 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

19 Benefits of biphasic dimerization Octene selectivity Dimerso l (3 reactors) industrial results Difasol (pilot results) Feed : 75% butenes, isobutene<2%

20 butenes octenes [Ni] organic phase ionic liquid : very low octene solubility dodecenes C12 C4 consecutive side-reactions are minimized Benefits of biphasic dimerization

21 Benefits of biphasic dimerization Feed : C4 Raffinate-2, 75% butenes, 20 tons per hour  decrease catalyst consumption  decrease reactor volume

22 Synthesis of Dimethylbutenes

23 Dimethylbutenes : key intermediates for fine chemicals insecticide Danitol TM (by Sumitomo) musk perfume Tonalid TM

24 à Industrial production by Sumitomo (1983) J Ni homogeneous catalyst J high 2,3-DMB selectivity (>70%/total hexenes) K elaborate catalyst formula with basic PR 3 L toluene as solvent L solvent separation needs an efficient distillation column L no catalyst recycling (destruction with NaOH) The simplest way of DMB synthesis : Selective propene dimerization with PR 3 ligand : regioselectivity > 70% [Ni]

25 Propene dimerization in chloroaluminates lSolvent : Acidic chloroaluminate (BMIC : AlCl 3 : EtAlCl 2 ) * after 1 hour reaction time; P(Cy) 3 = tricyclohexylphosphine Phosphine effect lSame Phosphine effect is observed in chloroaluminate as in homogeneous system.

26 Competition for the phosphine between «soft » Ni and « hard » AlCl 3 [PR 3.NiR] + A - + Al 2 Cl 7 - [NiR] + A - + AlCl 3.PR 3 + AlCl 4 - regioselective non regioselective Propene dimerization in chloroaluminates

27 aromatic hydrocarbon Stabilisation of DMB selectivity by addition of small amounts of a weak organic competitive base [PR 3.NiR] + A - + Al 2 Cl B [PR 3.NiR] + A - + AlCl 3.B + AlCl 4 - Selective propene dimerization in chloroaluminates

28 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

29 oligomerization acid catalysis IL [RNi] + A - Al 2 Cl 7 - H + Examples of applications of ionic liquids in chloroaluminates

30 [RNi] + A - hydrocyanation oligomerisation acid catalysis IL Al 2 Cl 7 - H + Ni Examples of applications of ionic liquids in chloroaluminates hydroformylation selective hydrogenation IL [H 2 RhL 2 ] + A - HRh(CO) L 3 in non- chloroaluminates PF 6 -, BF 4 -, CF 3 SO 3 -, (CF 3 SO 2 ) 2 N -... HCo(CO) 3 L metathesis of functional olefins Ru

31 Ni-catalyzed Butadiene Hydrocyanation

32 Hydrocyanation of butadiene into adiponitrile Industrial catalyst : homogeneous nickel(0)-phosphite complexes

33 Hydrocyanation Model Reaction Catalytic system: Ni(cod) 2 + PPh 3 + substrate + ionic liquid

34 Hydrocyanation Selection of the ionic liquid Catalytic system: Ni(cod) 2 + PPh 3 + substrate + ionic liquid C. Vallée et al. / Journal of Molecular Catalysis A: Chemical 214 (2004) 71–81

35 Hydrocyanation charge free active species need to design special ligands to anchor the catalyst in the ionic phase

36 Hydrocyanation A wide range of ionic phosphorus ligands Advanced Synthesis and Catalysis (2005) accepted

37 Hydrocyanation No trace of nickel or phosphorus (detection limit = 5 ppm) + Ni(cod) 2 + substrate + [BMMIM][NTf 2 ]

38 Co-catalyzed Olefin Hydroformylation

39 1 st GENERATION H Co (CO) bar °C Homogeneous catalysis Basic oracidic extraction ofCo BASF, EXXON. SHELL (PBu 3 ). Olefins  C 4 Propene Olefin hydroformylation: industrial processes Biphasic catalysis

40 Olefin hydroformylation the challenge : to develop an efficient process to hydroformylate higher (internal) olefins with an efficient and simple catalyst recovery

41 Olefin hydroformylation : why ionic liquids ? better solubility of olefins in IL than in water 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)

42 Co 2 (CO) 8 2 HCo(CO) 4 active cobalt catalyst : neutral H 2 /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 Co 2 (CO) bases these ionic species have a good affinity for ionic liquids Olefin Hydroformylation : cobalt catalyst H 2 /CO - base H 2 /CO - base 6 HCo(CO) 4

43 CO/H 2 Cobalt catalyzed Hydroformylation of olefins ü the base may help in the generation of the active Co catalyst ü simple cobalt recovery ü no by-product generation

44 Cobalt catalyzed 1-hexene hydroformylation : results - conversion : > 98% - aldehyde selectivity : % - recycling of Co « relatively simple » - no need of specially design ligand mol H 1 = / mol Co / h - ligand : L/Co=2 - ionic liquid : 6 mL - substrate : hexene-1 : 15 mL - (co-solvent) heptane : 30 mL T = 130°C, P = 100bars Conversion Selectivity

45 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, P. Wasserscheid, T. Welton, Ionic Liquids in Synthesis, Wiley-VCH, Weinheim H. Olivier-Bourbigou, L. Magna, J Mol. Catal. A: Chemical, 2002, , 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, C. M. Gordon, Appl. Catal. A: General, 2001, 222, 1-2, 101. R. Sheldon, Chem. Commun., 2001, 23, Ionic Liquids in Catalysis

46 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