CATALYST AND A PROCESS FOR THE PRODUCTION OF ETHYLENICALLY UNSATURATED CARBOXYLIC ACIDS OR ESTER

Abstract

A catalyst including a modified silica support having a titanium modifier metal, and a catalytic metal on the modified silica support. A proportion of the modifier metal is present in the form of mononuclear titanium moieties or is derived from a mononuclear titanium cation source at the commencement of modification. The invention also discloses a corresponding modified silica support, a method of producing the catalyst or the modified silica support, and a process for preparing an ethylenically unsaturated acid or ester in the presence of the catalyst.

Claims

1. A catalyst comprising a modified silica support, the modified silica support comprising titanium modifier metal, and a catalytic metal on the modified silica support, wherein at least a proportion of the modifier metal is present in the form of mononuclear titanium moieties.

2. (canceled)

3. A modified silica support for a catalyst comprising a silica support and titanium modifier metal, wherein at least a proportion of the said modifier metal is present in the form of mononuclear titanium moieties.

4. (canceled)

5. The catalyst according to claim 1, wherein the mononuclear titanium moieties are derived from a mononuclear titanium cation source at the commencement of the modification.

6. The modified silica support according to claim 3, wherein the mononuclear titanium moieties are derived from a mononuclear titanium cation source at the commencement of the modification.

7. The modified silica support of claim 3, wherein the titanium is an adsorbate adsorbed on the silica support surface.

8. The modified silica support of claim 3, wherein the titanium moieties are titanium oxide moieties.

9. The modified silica support of claim 3, wherein the silica support is in the form of a silica gel.

10. The modified silica support or catalyst of claim 3, wherein the mononuclear titanium moieties are present in the support as part of a co-gel.

11. The catalyst according to claim 1, wherein the mononuclear titanium moieties are present in the modified silica support in an effective amount to reduce sintering and improve selectivity of the catalyst.

12. The modified silica support of claim 3, wherein at least 25% of titanium in the modified silica support is in mononuclear moieties or is derived from a titanium compound at the commencement of the modified silica formation with mononuclear titanium species at such levels.

13. The modified silica support of claim 3, wherein the level of titanium present is up to 7.6×10.sup.−2 mol/mol of silica.

14. The modified silica support of claim 3, wherein the level of titanium is between 0.067×10.sup.−2 and 7.3×10.sup.−2 mol/mol of silica.

15. The modified silica support of claim 3, wherein the level of titanium present is at least 0.1×10.sup.−2 mol/mol of silica.

16. The modified silica support according to claim 3, wherein the modified silica support is a calcined modified silica support.

17. The catalyst according to claim 1, wherein the catalytic metal is one or more alkali metals.

18. (canceled)

19. (canceled)

20. The catalyst according to claim 1, wherein the catalytic metal is present in the range 0.5-7.0 mol/mol titanium.

21-54. (canceled)

55. A catalyst comprising a modified silica support, the modified silica support comprising titanium modifier metal, and a catalytic metal on the modified silica support, wherein at least a proportion of the modifier metal is present in modifier metal moieties derived from a mononuclear titanium cation source at the commencement of the modification.

56. A modified silica support for a catalyst comprising a silica support and a titanium modifier metal, wherein at least a proportion of the said modifier metal is present in modifier metal moieties derived from a mononuclear titanium cation source at the commencement of the modification.

57. The modified silica support according to claim 56, wherein the titanium metal cation at the commencement of the modification is in a compound with one or more non-labile ligands attached to the titanium metal cations which non-labile ligands are selected from molecules with lone pair containing oxygen or nitrogen atoms able to form 5 or 6 membered rings with a titanium atom, including diones, diimines, diamines, diols, dicarboxylic acids or derivatives thereof such as esters, or molecules having two different such functional groups and in either case with the respective N or O and N or O atom separated by 2 or 3 atoms to thereby form the 5 or 6 membered ring.

58. The modified silica support according to claim 57, wherein the non-labile ligands form complexes with titanium.

59. A catalyst according to claim 1, wherein the catalytic metal is caesium.

Description

EXPERIMENTAL

[0192] Silica Support Description

Example 1 (Preparative)

[0193] Fuji Silysia CARiACT Q10 silica was dried in a laboratory oven at 160° C. for 16 hours, after which it was removed from the oven and cooled to room temperature in a sealed flask stored in a desiccator. This silica had a surface area of 333 m.sup.2/g, a pore volume of 1.0 ml/g, and an average pore diameter of 10 nm as determined by nitrogen adsorption/desorption isotherm analysis (Micromeretics Tristar II). A silanol number of 0.8 OH/nm.sup.2 was found through TGA analysis. This silica is primarily composed of spherical silica beads in the diameter range of 2.0-4.0 mm.

[0194] Ti Modification of Silica Supports

Example 2 (0.6 wt % Ti from Ti(.SUP.n.OPr).SUB.2.(acac).SUB.2.) (Monomer)

[0195] 0.330 g of Ti(.sup.nOPr).sub.4 (98%, Sigma Aldrich) was dissolved in 11 ml of 1-PrOH (99.7% anhydrous, Sigma Aldrich). To this solution, 0.348 g of acetyl acetone (Sigma Aldrich) was added and agitation was effected for 30 min at room temperature to allow Ti-complex formation. In a separate flask 10 g of the silica from Example 1 was weighed off. The weighed off silica was then added to the Ti-complex solution with agitation. Agitation was continued until all of the Ti-complex solution had been taken up into the pore volume of the silica. Once pore filling had been completed the Ti-modified silica was left for 16 hours in a sealed flask with periodic agitation. After this time the extra-porous solution was removed by filtration. This was followed by a drying step where the intra-porous organic solvent was removed by passing a flow of nitrogen gas over the wet Ti-modified silica at room temperature. Alternatively, the intra-porous solvent was removed on a rotary evaporator at reduced pressure. Once all of the solvent had been removed the Ti-modified silica support was calcined in a furnace at 500° C. under a flow of air with a heating ramp rate of 5° C./min and a final hold of 5 hours. Upon cooling this yielded the Ti modified silica support with a 100% Ti usage efficiency. The Ti load (wt %) on the Ti-modified support was determined via powder Energy Dispersive X-Ray Fluorescence analysis (Oxford Instruments X-Supreme8000).

Example 3 (1.1 wt % Ti from Ti(.SUP.n.OPr).SUB.2.(acac).SUB.2.) (Monomer)

[0196] A support modification as described in Example 2 was performed except that 0.665 g of Ti(.sup.nOPr).sub.4, 0.703 g of acetyl acetone was used. Additionally, 16 ml of 1-PrOH was used instead of 11 ml. This resulted in the Ti-complex adsorption step being conducted as a slurry phase type adsorption and a Ti adsorption efficiency of 99%.

Example 4 (0.6 wt % Ti from Ti(TEA)(.SUP.i.OPr)) (Monomer)

[0197] A support modification as described in Example 2 was performed except that 0.741 g of Ti(TEA)(.sup.iOPr) (80 wt % in 2-PrOH, Sigma Aldrich), and no acetyl acetone was used. Additionally, 20 ml of 1-PrOH was used instead of 11 ml. This resulted in a Ti adsorption efficiency of 57%.

Example 5 (1.0 wt % Ti from Ti(TEA)(.SUP.i.OPr)) (Monomer)

[0198] A support modification as described in Example 4 was performed except that 1.510 g of Ti(TEA)(.sup.iOPr) was used. This resulted in a Ti adsorption efficiency of 45%.

Example 6 (2.0 wt % Ti from Ti(TEA)(.SUP.i.OPr) (Monomer)

[0199] A support modification as described in Example 4 was performed except that 2.382 g of Ti(TEA(iOPr) was used. Additionally, 10 ml of toluene (99.8% anhydrous, Sigma Aldrich) was used to dissolve the Ti(TEA)(.sup.iOPr) precursor instead of 1-PrOH. This solution was then which was added to the silica that had be pre-pore filled with 10 ml of toluene. This resulted in a Ti adsorption efficiency of 58%.

Example 7 (Comparative) (3.9 wt % Ti from Ti(.SUP.n.OPr).SUB.4.) (Dimer)

[0200] A support modification as described in Example 4 was performed except that 2.613 g of Ti(.sup.nOPr).sub.4 was used and 20 ml of toluene was used instead of 1-PrOH. This resulted in a Ti adsorption efficiency of 95%.

Example 8 (Comparative) (1.8 wt % Ti from Ti(.SUP.n.OPr).SUB.4 .(Dimer)

[0201] A support modification as described in Example 6 was performed except that 1.039 g of Ti(.sup.nOPr).sub.4 was used. This resulted in a Ti adsorption efficiency of 100%.

[0202] Cs Modification of Modified Supports

Example 9 (3.5 wt % Cs, 0.5 wt % Ti)

[0203] 0.514 g of CsOH.H.sub.2O (99.5% Sigma Aldrich) was weighed out in a glovebox and dissolved in 20 ml of a 9:1 v/v MeOH:H.sub.2O (MeOH from Sigma Aldrich, H.sub.2O as demineralised water) solvent mixture. 10 g of the modified silica from Example 2 was added to the CsOH solution with agitation. Agitation was continued for an additional 15 min after which the sample was left for 16 hours in a sealed flask with periodic agitation. After this time the extra-porous solution was removed by filtration. This was followed by a drying step where the intra-porous solvent was removed by passing a flow of nitrogen gas over the wet Cs/Ti-modified silica at room temperature. Alternatively, the intra-porous solvent was removed on a rotary evaporator at reduced pressure. Following this step the catalyst beads were placed into a drying oven at 120° C. and left to dry for 16 hours. Upon cooling this yielded the Cs/Ti/SiO.sub.2 catalyst with a 90% Cs usage efficiency. The Cs load (wt %) on the catalyst was determined via powder Energy Dispersive X-Ray Fluorescence analysis (Oxford Instruments X-Supreme8000).

Example 10 (4.0 wt % Cs, 0.5 wt % Ti)

[0204] A catalyst was prepared as described in Example 9 except that 0.583 g of CsOH.H.sub.2O was used.

Example 11 (4.4 wt % Cs, 0.5 wt % Ti)

[0205] A catalyst was prepared as described in Example 9 except that 0.647 g of CsOH.H.sub.2O was used.

Example 12 (5.3 wt % Cs, 0.5 wt % Ti)

[0206] A catalyst was prepared as described in Example 9 except that 0.795 g of CsOH.H.sub.2O was used.

Example 13 (6.6 wt % Cs, 1.0 wt % Ti)

[0207] A catalyst was prepared as described in Example 9 except that 1.01 g of CsOH.H.sub.2O was used and modified silica from Example 3 was used.

Example 14 (7.7 wt % Cs, 1.0 wt % Ti)

[0208] A catalyst was prepared as described in Example 13 except that 1.17 g of CsOH.H.sub.2O was used.

Example 15 (8.4 wt % Cs, 1.0 wt % Ti)

[0209] A catalyst was prepared as described in Example 13 except that 1.30 g of CsOH.H.sub.2O was used.

Example 16 (9.9 wt % Cs, 1.0 wt % Ti)

[0210] A catalyst was prepared as described in Example 13 except that 1.55 g of CsOH.H.sub.2O was used.

Example 17 (4.0 wt % Cs, 0.6 wt % Ti)

[0211] A catalyst was prepared as described in Example 9 except that 0.59 g of CsOH.H.sub.2O was used and modified silica from Example 4 was used.

Example 18 (4.8 wt % Cs, 0.6 wt % Ti)

[0212] A catalyst was prepared as described in Example 17 except that 0.71 g of CsOH.H.sub.2O was used.

Example 19 (5.2 wt % Cs. 0.6 wt % Ti)

[0213] A catalyst was prepared as described in Example 17 except that 0.78 g of CsOH.H.sub.2O was used.

Example 20 (6.3 wt % Cs, 0.6 wt % Ti)

[0214] A catalyst was prepared as described in Example 17 except that 0.95 g of CsOH.H.sub.2O was used.

Example 21 (6.5 wt % Cs, 1.0 wt % Ti)

[0215] A catalyst was prepared as described in Example 9 except that 0.99 g of CsOH.H.sub.2O was used and modified silica from Example 5 was used.

Example 22 (7.5 wt % Cs, 0.9 wt % Ti)

[0216] A catalyst was prepared as described in Example 21 except that 1.15 g of CsOH.H.sub.2O was used.

Example 23 (9.8 wt % Cs, 0.9 wt % Ti)

[0217] A catalyst was prepared as described in Example 21 except that 1.54 g of CsOH.H.sub.2O was used.

Example 24 (9.3 wt % Cs, 1.8 wt % Ti)

[0218] A catalyst was prepared as described in Example 9 except that 1.46 g of CsOH.H.sub.2O was used and modified silica from Example 6 was used.

Example 25 (10.5 wt %, 1.8 wt % Ti)

[0219] A catalyst was prepared as described in Example 24 except that 1.67 g of CsOH.H.sub.2O was used.

Example 26 (Comparative) (12.4 wt % Cs, 3.4 wt % Ti)

[0220] A catalyst was prepared as described in Example 9 except that 2.04 g of CsOH.H.sub.2O was used and modified silica from Example 7 was used.

Example 27 (Comparative) (14.0 wt % Cs, 3.4 wt % Ti)

[0221] A catalyst was prepared as described in Example 26 except that 2.35 g of CsOH.H.sub.2O was used.

Example 28 (Comparative) (15.2 wt % Cs, 3.3 wt % Ti)

[0222] A catalyst was prepared as described in Example 26 except that 2.58 g of CsOH.H.sub.2O was used.

Example 29 (Comparative) (18.2 wt % Cs, 3.2 wt % Ti)

[0223] A catalyst was prepared as described in Example 26 except that 3.21 g of CsOH.H.sub.2O was used.

Example 30 (Comparative) (9.4 wt % Cs, 1.6 wt % Ti)

[0224] A catalyst was prepared as described in Example 9 except that 2.04 g of CsOH.H.sub.2O was used and modified silica from Example 8 was used.

Example 31 (Comparative) (10.6 wt % Cs, 1.6 wt % Ti)

[0225] A catalyst was prepared as described in Example 30 except that 1.61 g of CsOH.H.sub.2O was used.

Example 32 (Catalytic Performance Testing)

[0226] Catalysts from Example 9 to Example 31 were tested for the reaction of methyl propionate and formaldehyde in a labscale microreactor. For this, 3 g of catalyst was loaded into a fixed bed reactor with an internal tube diameter of 10 mm as either crushed and sieved (0.1-1.0 mm particle size) or whole bead (2.0-4.0 mm particle size) particles. The reactor was heated to 330° C. and preconditioning was performed by feeding a vaporised stream comprising of 70 wt % methyl propionate, 20 wt % methanol, 6 wt % water and 4 wt % formaldehyde from a vaporiser fed by a Gilson pump at 0.032 ml/min. This preconditioning was continued overnight. After preconditioning, a feed stream comprising of 75.6 wt % methyl propionate, 18.1 wt % methanol, 5.7 wt % formaldehyde and 0.6 wt % water, was pumped by a Gilson pump to a vaporiser set at 330° C. before being fed to the heated reactor set at 330° C. containing the catalyst. The reactor exit vapour was cooled and condensed with samples being collected at five different liquid feed rates (between 0.64-0.032 ml/min) so as to obtain conversions at varying vapour/catalyst contact times. The liquid feed and condensed ex-reactor liquid products were analysed by a Shimadzu 2010 Gas Chromatograph with a DB1701 column. The compositions of the samples were determined from the respective chromatograms and yields and selectivities at varying contact times determined. Activity was defined as the inverse of the contact time, in seconds, required to obtain 10% MMA+MAA yield on methyl propionate fed and was determined via an interpolation on a contact time vs. MMA+MAA yield graph. This interpolated contact time was then used to obtain the MMA+MAA selectivity at 10% MMA+MAA yield.

TABLE-US-00001 TABLE 1 Activity and MMA + MAA selectivity results for catalysts prepared on the Ti modified support examples tested as whole beads. Activity Ti Cs at 10% MMA + load load Cs:Ti MMA + MAA Ti (wt (wt (molar MAA selectivity Example nuclearity %) %) ratio) yield (1/s) (%) Example 9 1 0.5 3.5 2.4 0.22 94.7 Example 10 1 0.5 4.0 2.7 0.29 95.7 Example 11 1 0.5 4.4 3.0 0.35 95.6 Example 12 1 0.5 5.3 3.7 0.35 96.3 Example 13 1 1.0 6.6 2.4 0.46 94.2 Example 14 1 1.0 7.7 2.7 0.55 95.4 Example 15 1 1.0 8.4 3.0 0.69 94.7 Example 16 1 1.0 9.9 3.6 0.63 95.1 Example 17 1 0.6 4.0 2.4 0.30 94.7 Example 18 1 0.6 4.8 2.9 0.38 95.2 Example 19 1 0.6 5.2 3.2 0.51 95.3 Example 20 1 0.6 6.3 3.9 0.46 96.3 Example 21 1 1.0 6.5 2.5 0.55 93.5 Example 22 1 0.9 7.5 2.9 0.73 94.4 Example 23 1 0.9 9.8 3.9 0.79 95.0 Example 26 2 3.4 12.4 1.3 0.74 92.8 (comp) Example 27 2 3.4 14.0 1.5 1.00 92.8 (comp) Example 28 2 3.3 15.2 1.7 1.13 93.1 (comp) Example 29 2 3.2 18.2 2.1 0.55 90.1 (comp)

TABLE-US-00002 TABLE 2 Activity and MMA + MAA selectivity results for catalysts prepared on the Ti modified support examples tested as crushed beads. Activity Ti Cs at 10% MMA + load load Cs:Ti MMA + MAA Ti (wt (wt (molar MAA selectivity Example nuclearity %) %) ratio) yield (1/s) (%) Example 24 1 1.8 9.3 1.8 1.08 93.8 Example 25 1 1.8 10.5 2.1 1.22 93.2 Example 30 2 1.6 9.4 2.1 1.02 81.7 (comp) Example 31 2 1.6 10.6 2.4 1.08 83.5 (comp)

Example 33 (Accelerated Ageing Tests)

[0227] Catalyst sintering resistance was assessed in an accelerated ageing test. For this, 1 g of catalyst was loaded into a U-tube stainless steel reactor and loaded into an oven. The oven was heated to 385° C. and a stream of nitrogen (10 ml/min) was passed through a saturating vaporiser containing water that was heated to 92° C. This ensured that a feed stream with a water partial pressure of 0.75 bara was passed over the catalyst heated to 385° C. Periodically the surface area of the catalyst samples was determined ex-situ using nitrogen adsorption/desorption isotherm analysis (Micromeretics Tristar II). The measured surface area values were used to determine sintering rates constants for each catalyst and is described as g.sup.3.Math.m.sup.−6.Math.d.sup.−1. The higher the sintering rate constant, the lower the sintering resistance of the catalyst. This test was performed on catalysts from Example 9 to Example 12.

TABLE-US-00003 TABLE 3 Accelerated ageing data for the catalysts containing Ti as a modifier. Sintering rate Surface area Catalyst constant at time (days) activity (g.sup.3 .Math. Example 1 7 14 21 28 (1/s) m.sup.−6 .Math. d.sup.−1) Example 9 187 159 144 140 140 0.22 7.70E−09 Example 10 171 151 124 130 127 0.29 1.09E−08 Example 11 153 115 111 87 103 0.35 3.16E−08 Example 12 119 98 86 82 89 0.35 3.51E−08

[0228] Attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference.

[0229] All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive.

[0230] Each feature disclosed in this specification (including any accompanying claims, abstract and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.

[0231] The invention is not restricted to the details of the foregoing embodiment(s). The invention extends to any novel one, or any novel combination, of the preferred, typical or optional invention features disclosed in this specification (including any accompanying claims, abstract or drawings), or to any novel one, or any novel combination, of the preferred, typical or optional invention steps of any method or process so disclosed.