Mixed oxide catalyst and a process for the production of ethylenically unsaturated carboxylic acids or esters
The invention relates to a catalyst for the reaction of formaldehyde with a carboxylic acid or ester to produce an ethylenically unsaturated carboxylic acid or ester, preferably α, β ethylenically unsaturated carboxylic acids or ester. The catalyst includes a metal oxide having at least two types of metal cations, M 1 and M 2 , wherein M 1 is at least one metal selected from group 3 or 4 in the 4 th to 6 th periods of the periodic table, group 13 in the 3 rd to 5 th periods of the periodic table, or the remaining elements in the lanthanide series and M 2 is at least one metal selected from group 5 in the 5 th or 6 th periods of the periodic table or group 15 in the 4 th or 5 th periods of the periodic table. The production includes reacting formaldehyde with a carboxylic acid or esterin the presence of the catalyst effective to catalyze the reaction.
1. A catalyst for the reaction of a suitable source of formaldehyde with a carboxylic acid or ester to produce an ethylenically unsaturated carboxylic acid or ester, wherein the catalyst comprises a metal oxide having at least two metal cations, M 1 and M 2 , wherein M 1 is at least one metal selected from group 3 or 4 in the 4 th to 6 th periods of the periodic table, group 13 in the 4 th to 5 th periods of the periodic table, or the remaining elements in the lanthanide series including scandium, yttrium, the lanthanide elements, titanium, zirconium, hafnium, gallium, and indium and M 2 is at least one metal selected from group 5 in the 5 th or 6 th periods of the periodic table or group 15 in the 4 th or 5 th periods of the periodic table including niobium, tantalum, arsenic, and antimony and optionally, M 3 or M 4 , wherein M 3 is selected from groups 1 and 2 of the periodic table and M 4 is selected from group 14 of the periodic table, wherein the ratio M 1 :M 2 is in the range of from 5:1 to 1:5, and wherein the metal oxide catalyst compound of the invention does not include other metal types above a level 0.1 mol % other than the types M 1 , M 2 , M 3 , or M 4 .
2. A catalyst according to claim 1 , wherein M 1 are cations in the 3+ oxidation state.
3. A catalyst according to claim 1 , wherein M 2 are cations in the +5 oxidation state.
4. A catalyst according to claim 1 , wherein the combinations of metal oxides for use in the present invention may be selected from the group consisting of: Ti\Sb oxide; Ga\Sb oxide; In\Sb oxide; Zr\Nb oxide; Ga\Nb oxide; Y\Nb oxide; La\Nb oxide; and La\Ta oxide which oxides are either unsupported or supported on a suitable support comprising alumina, silica, silicon nitride, colloidal silica, titania or aluminium phosphate.
5. A catalyst according to claim 1 , wherein further metals or cations of M 3 and/or M 4 are present in the mixed metal oxide.
6. A catalyst according to claim 1 , wherein the formula for the metal oxide is M 1 n M 2 m M 3 q M 4 r O p wherein M 1 is a cation, and M 2 is a cation, n, m and p may be a positive integer or decimal number and q and r may be a positive integer or decimal number and wherein:
at least one of M 3 or M 4 is a metal or cation.
7. A catalyst according to claim 1 , wherein a binder is used and forms up to 50 wt % of the catalyst.
8. A process in the presence of a catalyst according to claim 1 for the production of an ethylenically unsaturated carboxylic acid or ester comprising the step of reacting a suitable source of formaldehyde with a carboxylic acid or ester.
9. A process for the production of ethylenically unsaturated carboxylic acids or esters according to claim 8 , wherein the carboxylic acid or ester reactant of the present invention is of formula R 3 —CH 2 —COOR 4 wherein R 4 is either hydrogen or an alkyl group and R 3 is either hydrogen, an alkyl or aryl group.
10. A process for the production of ethylenically unsaturated carboxylic acids or esters according to claim 8 , wherein the ethylenically unsaturated acid or ester produced by the process is selected from the group consisting of: methacrylic acid, acrylic acid, methyl methacrylate, ethyl acrylate and butyl acrylate.
11. The catalyst according to claim 6 , wherein M 1 is a 3+ cation and M 2 is a 5+ cation.
12. The process of claim 8 wherein the reaction is carried out in the presence of an alcohol.
13. The process of claim 10 wherein the ethylenically unsaturated acid or ester produced by the process is methyl methacrylate.
14. The catalyst according to claim 1 , wherein the ethylenically unsaturated carboxylic acid or ester is selected from α, β ethylenically unsaturated carboxylic acids or esters.
15. The process of claim 8 , wherein metals or cations M 3 and/or M 4 are present in the mixed metal oxide.
16. A catalyst for the reaction of a suitable source of formaldehyde with a carboxylic acid or ester to produce an ethylenically unsaturated carboxylic acid or ester, wherein the catalyst comprises a metal oxide having at least two metal cations, M 1 and M 2 , wherein M 1 is at least one metal selected from group 3 or 4 in the 4 th to 6 th periods of the periodic table, group 13 in the 4 th to 5 th periods of the periodic table, or the remaining elements in the lanthanide series including scandium, yttrium, the lanthanide elements, titanium, zirconium, hafnium, gallium, and indium and M 2 is at least one metal selected from group 5 in the 5 th or 6 th periods of the periodic table or group 15 in the 4 th or 5 th periods of the periodic table including niobium, tantalum, arsenic, and antimony and at least one of M 3 or M 4 , wherein M 3 is selected from groups 1 and 2 of the periodic table and M 4 is selected from group 14 of the periodic table, wherein the ratio M 1 :M 2 is in the range of from 5:1 to 1:5, and wherein the metal oxide catalyst compound of the invention does not include other metal types above a level 0.1 mol % other than the types M 1 , M 2 , M 3 , or M 4 .