Patent EA-003858-B1 (EA)
Title: Catalysts consisting of metals on hydrotalcite-based carrier materials
Inventor: OLSBYE UNNI
IPC: C07C5/02
Filed: 1999-12-22
Abstract: 1. A catalyst comprising at least one metal loaded on a hydrotalcite-based carrier material which has the following formula in it's uncalcined form M<2+>aM<3+>b (A<N-1>)c(OH)2a+3b-nc(xH2O, wherein M<2+> is at Mg<2+>; and M<3+> is Al<3+> or Ga<3+>l; A is an n-valent anion, n is 1 or 2, c is 1 or 2, and a and b are positive numbers, a > b; x is 4, the catalyst being prepared by: a) addition of at least one metal salt or complex to the carrier material, of which the carrier material is (at least partly) in, or transformed to, the hydrotalcite phase during the metal addition step; b) followed by washing, and c) calcination. 2. A (de) hydrogenation catalyst comprising at least one metal selected from the group VIII of the periodical table of elements loaded on a hydrotalcite-based carrier material which has the following formula in it's uncalcined form M<2+>aM<3+>b (A<N-1>)c(OH)2a+3b-nc(xH2O, wherein M<2+> is at Mg<2+>; and M<3+> is Al<3+> or Ga<3+>l; A is an n-valent anion, n is 1 or 2, c is 1 or 2, and a and b are positive numbers, a > b; x is 4, the catalyst being prepared by: a) addition of at least one metal salt or complex to the carrier material, of which the carrier material is (at least partly) in, or transformed to, the hydrotalcite phase during the metal addition step; b) followed by washing, and c) calcination. 3. The catalyst of Claim 1 or 2, wherein A is OH and/or CO3; CH3COO; or other inorganic or organic acid residues; n is 1 or 2. 4. The catalyst of the claims 1-3, wherein the at least one metal salt or complex has been added in an aqueous solution. 5. The catalyst of claim 4, wherein the at least one metal salt or complex has been added in a neutral aqueous solution. 6. The catalyst of the claim 4, wherein the at least one metal salt or complex has been added in an acid aqueous solution. 7. The catalyst of the claim 6, wherein the pH of the acid aqueous solution is lower than 5, and preferably lower than 4. 8. The catalyst of the claims 6 or 7, wherein the at least one metal salt or complex has been added in an aqueous inorganic acid solution. 9. The catalyst of the claim 8, wherein the addition of the at least one metal salt or complex has been performed in an aqueous HCl solution. 10. The catalyst of the claim 6 or 7, wherein the acid aqueous solution is an aqueous solution of an organic acid. 11. The catalyst of the claim 10, wherein the organic acid is acetic acid. 12. The catalyst of the claims 1 or 2, wherein the at least one metal salt or complex has been added in an organic solution. 13. The catalyst of claim 12, wherein the addition of the at least one metal salt or complex has been performed in an ethanol solution. 14. The catalyst of the claim 1 and 2, wherein the at least one metal salt or complex has been added by wet impregnation. 15. The catalyst of the claims 1-14, wherein the contact time between the metal containing solution and the carrier material has been between 0.01 and 30 hours, preferably between 0.05 and 5 hours. 16. The catalyst of the claims 1 or 2, wherein the at least one metal salt or complex has been added by incipient impregnation. 17. The catalyst of the claims 1-16, wherein the hydrotalcite based carrier has been subject to preparation by mixing Mg (NO3)3 x6H2O and Al (NO3)3x 9H2O dissolved in water with a basic aqueous solution containing OH and CO3 anions. 18. The catalyst of the claim 17, wherein the hydrotalcite based carrier has been subject to drying. 19. The catalyst of the claim 18, wherein the hydrotalcite based carrier has been subject to calcination. 20. The catalyst of the claims 19, wherein the hydrotalcite based carrier has been subject to suspension. 21. The catalyst of the claims 1-20, wherein the hydrotalcite based carrier has been subject to wet impregnation as defined in the claim 14 and anion exchange. 22. The catalyst of the claims 1-21, wherein the hydrotalcite based carrier has been subject to a combination of any of the treatments of the claims 20-21. 23. The catalyst of the claims 1-19, wherein the hydrotalcite based carrier has been calcined at a temperature of 700 to 1200 C, preferably 700-800 degree C. 24. The catalyst of the claims 1-23, wherein the final catalyst calcination takes place at a temperature of 400 to 1200 C, preferably 560-800 degree C. 25. The catalyst of the claims 1-24, wherein a binder is admixed. 26. The catalyst of the claims 2-29, wherein the hydrotalcite based carrier has been impregnated by at least one metal selected from the group IVA of the periodical table of the elements. 27. The catalyst of the claim 26, wherein the hydrotalcite based carrier has been impregnated by at least one metal selected from the group VIII, at least one metal selected from the group IVA, and optionally at least one metal selected from the group IA of the periodical table of the elements. 28. The catalyst of the claims 2-25, wherein the hydrotalcite based carrier has been impregnated by at least one salt or complex of Pt as the group VIII of the periodical table of the elements metal. 29. The catalyst of the claims 26 or 27, wherein the hydrotalcite based carrier has been impregnated by at least one salt or complex of Sn from the group IVA of the periodical table of the elements. 30. The catalyst of the claims 28 or 29, wherein the hydrotalcite based carrier has been impregnated by at least one salt or complex of Pt as the group VIII and by at least one salt or complex of Sn as the group IVA of the periodical table of the elements metal. 31. The catalyst of the claims 26 or 27, wherein the salt of Pt is H2PtCl6 x 6H2O. 32. The catalyst of the claims 30-33, wherein the salt of Sn is SnCl2 x 2H2O. 33. The use of a catalyst of any of the claims 2-32 in dehydrogenation reactions. 34. The use of a catalyst of any of the claims 2-32 in the dehydrogenation of alkanes. 35. The use of a catalyst of any of the claims 2-32 in the dehydrogenation of C2-C4 alkanes. 36. The use of a catalyst of any of the claims 2-32 in the dehydrogenation of propane. 37. The use of a catalyst of any of the claims 2-32 in the hydrogenation of unsaturated hydrocarbons.