SILP (Supported Ionic Liquid Phase) catalysis in Gas-Phase Hydroformylation and Carbonylation

Transcription

1 SIL (Supported Ionic Liquid hase) catalysis in Gas-hase Hydroformylation and Carbonylation Anders Riisager, Rasmus Fehrmann Department of Chemistry, Technical University of Denmark, Denmark Marco Haumann, eter Wasserscheid Lehrstuhl für Chemische Reaktionstechnik, Universität Erlangen-Nürnberg, Germany

2 Applications of ionic liquids Electrochemistry batteries electroplating dye dye sensitised solar solar cells cells Analytics & sensors GC GC // HLC HLC MS MS matrices humidity sensors reaction monitoring Engineering fluids fluids extraction extractive distillation lubrication process machinery material and and particle particle preparation Alternative solvents synthesis biphasic catalysis biocatalysis SIL SIL catalysis

3 Characteristics of ionic liquids Ionic nature Liquids below 100 C No detectable vapour pressure (at room temperature) Tuneable properties ( designer solvents ) High thermal stability Expensive solvents ( /kg) High viscosity / low gas solubility

4 Biphasic catalysis using ionic liquids Recycling of transition metal complex Recycling of ionic liquid itself reservation of ionic liquid nature around the dissolved catalyst Substrate roduct Catalyst complex dissolved in IL Many catalysts are highly active in ionic liquids Low gas solubility due to high viscosity of ionic liquid Mass transport limitations Low utilisation of ionic liquid/catalyst

5 Supported Ionic Liquid hase (SIL) Supported liquid phase (SL) Supported aqueous phase (SA) Substrate roduct SIL vs. SL/SA SIL catalyst particle orous network Increased stability and improved handling system can be adapted to water sensitive systems activation effects already known from ionic liquids can be incorporated. OC H Rh CO OC H Rh CO Ionic Liquid film

6 SIL vs. heterogeneous catalysis SIL active site active surface Heterogeneous catalysis mainly defects, corners, edges attribute to activity SIL catalysis coating of defects with ionic liquid Thin film allows complete catalyst utilisation

7 SIL catalysed hydroformylation OC H Rh CO R + CO/H 2 OC H Rh CO R CHO + R CHO HRh(CO) =

8 Continuous fixed bed reactor setup

9 Silica support pre-treatment NH 3 -TD studies using thermally pre-treated and untreated silica support NH3 desorption, a.u. re-treatment: o o C, C, air, air, 30h 30h Untreated T max = 150 o C NH 3d = 270 μmol/g T max = 145 o C NH 3d = 69 μmol/g Temp / o C 25 % acidic sites remaining

10 31 -NMR, pre-treated silica Rh-sulfoxantphos/[BMIM][n-C 8 H 17 O-SO 3 ] (L/Rh = 10, α = 0.1, c Rh = 0.2 wt%) Rh (19%) (27%) H O O O Si Si Si (54%) H MAS 31 -NMR, SIL catalyst (ppm) 31 -NMR, Rh in solution -60 Rh A. Riisager et al., Angew. Chem. Int. Ed. 2005, 44, M

11 in-situ IR, pre-treated silica ν(co) ν(co) Complex system Solvent ea-isomer cm 1 ee-isomer cm 1 Ref. Rh-SX-SIL [BMIM] [n-c 8 H 17 O-SO 3 ] 1994, , 1964 Riisager et al. [HRh(CO) 2 (SX)] [BMIM][F 6 ] 1985, , 1967 Dupont, v. Leeuwen et al. [HRh(CO) 2 (xantphos)] benzene 1991, , 1969 v. Leeuwen et al. [HRh(CO) 2 (thixantphos)] cyclohexane 1999, , 1977 v. Leeuwen et al. A. Riisager et al., Angew. Chem. Int. Ed. 2005, 44, 815.

12 C3-Hydroformylation Rh-(-)-SIL CO / H 2 CHO + CHO

13 Long term stability [BMIM][n-C 8 H 17 O-SO 3 ], (α = 0.1), c Rh = 0.2 wt%, 100 C, CO:H 2 1:1) TOF / h TOF n-butanal n-butanal / % Time / h M. Haumann et al., Ind. Eng. Chem. Res. 2005, 44, 9853.

14 Catalyst re-activation [BMIM][n-C 8 H 17 O-SO 3 ], (α = 0.1), c Rh = 0.2 wt%, 100 C, CO:H 2 1:1) TOF n-butanal TOF / h min vacuum 10 min vacuum Time / h M. Haumann et al., Ind. Eng. Chem. Res. 2005, 44, n-butanal / %

15 Kinetics: p propene [BMIM][n-C 8 H 17 O-SO 3 ], (α = 0.1), c Rh = 0.2 wt%, 100 C, CO:H 2 1:1) 0-1 ln(rate) -2-3 average average slope slope = = C 130 C 120 C 104 C 82 C 65 C ln p propene M. Haumann et al., Ind. Eng. Chem. Res. 2005, 44, 9853.

16 Kinetics: residence time [BMIM][n-C 8 H 17 O-SO 3 ], (α = 0.1), c Rh = 0.2 wt%, 100 C, CO:H 2 1:1) ln(p propene )-ln(p propene,0 ) C 80 C 100 C 120 C Residence time τ / s M. Haumann et al., Ind. Eng. Chem. Res. 2005, 44, 9853.

17 Activation energy [BMIM][n-C 8 H 17 O-SO 3 ], (α = 0.1), c Rh = 0.2 wt%, C, CO:H 2 1:1) 0-1 p propene residence time τ ln k -2-3 E A = A kj kj mol mol -1-1 (Lit.: (Lit.: to to kj kj mol mol -1-1 )) T -1 / K -1 M. Haumann et al., Ind. Eng. Chem. Res. 2005, 44, 9853.

18 CO 2 co-feed [BMIM][n-C 8 H 17 O-SO 3 ], (α = 0.1), c Rh = 0.2 wt%, C, CO:H 2 1:1) 0,16 0,14 0,12 CO 2 CO 2 repeated CO 2 average He Conversion 0,10 0, % 0,06 0, % Rate Rate acceleration by by CO CO p co-feed / bar

19 C4-Hydroformylation Rh-(-)-SIL CO / H 2 CHO + CHO

20 Kinetics: catalyst loading [BMIM][n-C 8 H 17 O-SO 3 ], (α = 0.1), p 1-butene = 1.9 bar, 100 C, CO:H 2 1:1) -3,6-3,8-4,0 ln r eff -4,2-4,4-4,6 slope slope = (kinetic regime) -4,8-5,0-7,4-7,2-7,0-6,8-6,6-6,4-6,2-6,0-5,8 ln C Rh M. Haumann et al., Adv. Syn. Cat. 2006, submitted.

21 Kinetics: p hydrogen / p carbonmonoxide ln p H CO H ln r eff slope slope (H (H 2 ) 2 ) = slope slope (CO) (CO) = ln p CO M. Haumann et al., Adv. Syn. Cat. 2006, submitted.

22 Raffinate II ure 1-butene feedstock expensive Raffinate II (from C4 cut) attractive, but: Butene isomers mixture, n-butane, iso-butane etc. SIL hydroformylation CHO Rh(sulfoxantphos)-SIL CO / H 2 C 4 H 10 Isomerisation C 4 H 10

23 Raffinate II Temperature / C TOF / h-1 S Aldehydes / % S n-pentanal / % p Total = 10 bar, p RaffinateII = 3.6 bar, p 1-butene = 1.16 bar, CO:H 2 = 1:1, [Rh] = 0.2%-w, α = 0.1 High selectivity towards linear products Lower chemoselectivity at lower temperature Competing hydrogenation reaction Lower activity Catalyst will convert only terminal alkenes

24 MeOH Carbonylation CH 3 OH Rh-(I 2 )SIL CO CH 3 CO 2 H CH 3 CO 2 CH 3 CH 3 OCH 3

25 Monsanto SIL catalyst Synthesis SiO 2.J. Dyson et al., Chem. Comm. 2003, 508. in-situ IR spectroscopy [BMIM] [Rh(CO) 2 I 2 ] ν CO = 2062, 1990 cm -1 (CH 2 Cl 2 ) Bu I I N Rh H CO CO Me N ν CO = 2076, 2006 cm -1 Ionic Ionic liquid liquid optimisation / cm A. Riisager et al., Chem. Comm. 2006, 1.

26 MeOH carbonylation ressure / bar Conversion / % STY / mol L -1 h -1 Selectivity / % AcOR DME AcOH AcOMe DME a) a) double space velocity Fixed-bed reactor setup (180 C, 20 bar) Steady-state conversion after 40 min high acetyl selectivity (>98 %) very low AcOH / AcOMe ratio product distribution influenced by reaction conditions A. Riisager et al., Chem. Comm. 2006, 1.

27 Summary C3/C4 hydroformylation SIL catalyst concept successfully applied in hydroformylation of propene Ionic liquid layer required for good catalyst performance Ligand surface interaction reduces effective L/Rh ratio Support surface acidity is key factor determining catalyst performance Homogeneous nature of catalyst verified by in-situ spectroscopy Kinetic data support spectroscopic findings (E A = 64 kj mol -1 ) No mass-transport limitations Continuous fixed bed technology possible Highly active and selective catalysts stable up to 700 hrs time-on-stream Reactivation of used catalysts possible MeOH carbonylation No catalyst recycling or leaching roduct flashing without presence of catalyst Ionic liquid no inert solvent

28 Outlook Support material Ionic Liquid Catalyst system Continuous, gas-phase reactions (combined with scco 2 ) Advanced materials & processes: reaction sequences shape-selective supports SIL-membranes/nano-SIL

29 Acknowledgements Anders Riisager Bettina Jørgensen Rasmus Fehrmann eter Wasserscheid Babu Suresh Kumar Gorle Berthold Melcher Daniela Regelein Joni Katrin Dentler Stefan Dowy Florian Enzenberger