Catalysator element comprised of a mixed metal oxide hydrotalcite-like compound

1. A catalysator element, comprising:

a solid support coated with a calcined mixed metal oxide hydrotalcite-like compound,

wherein said calcined mixed metal oxide hydrotalcite-like compound comprises at least one bivalent metal (M 2+ ) and at least one trivalent metal (M 3+ ), and

wherein:

said at least one bivalent metal (M 2+ ) is selected from the group consisting of Co 2+ , Cu 2+ , Fe 2+ , Mn 2+ , Zn 2+ , Ni 2+ , Ag 2+ , Ca 2+ , Pt 2+ ; Pd 2+ ; Cd 2+ ; Mo 2+ ; W 2+ ; Ru 2+ ; Sr 2+ ; Ba 2+ ; Nd 2+ and mixtures thereof, and

wherein said at least one trivalent metal (M 3+ ) is selected from the group consisting of Ce 3+ , Al 3+ , Mn 3+ , Fe 3+ , Hf 3+ , Co 3+ , V 3+ , Ti 3+ , Zr 3+ , Y 3+ , La 3+ and Pr 3+ and mixtures thereof; or

wherein said at least one trivalent metal (M 3+ ) in combination with Al 3+ is selected from the group consisting of Ce 3+ , Mn 3+ , Fe 3+ , Hf 3+ , Co 3+ , V 3+ , Ti 3+ , Zr 3+ , Y 3+ , La 3+ and Pr 3+ and mixtures thereof; and

wherein said catalysator element provides conversion of isocyanic acid to NH 3 via at least one of hydrolysis and conversion of urea to NH 3 .

2. The catalysator element according to claim 1 , wherein at least one bivalent metal (M 2+ ) and said at least one trivalent metal (M 3+ ) are selected from the group of non-stoichiometric combinations consisting of CoAlCe; CoAlMn; CoAlFe; CoAlCo; CoAlV; CoAlTi; CoAlHf; CoAlPr; CoAlLa; CuAlCe; FeAlCe; ZnAlCe; NiAlCe; AgAlCe; CaAlCe; PtAlCe; PdAlCe; CdAlCe; MoAlCe; WAlCe; RuAlCe; SrAlCe; BaAlCe; NdAlCe; CuAlMn; FeAlMn; ZnAlMn; NiAlMn; AgAlMn; CaAlMn; PtAlMn; PdAlMn; CdAlMn; MoAlMn; WAlMn; RuAlMn; SrAlMn; BaAlMn; NdAlMn; CuAlFe; FeAlFe; ZnAlFe; NiAlCe; AgAlCe; CaAlCe; PtAlCe; PdAlCe; CdAlCe; MoAlCe; WAlCe; RuAlCe; SrAlCe; BaAlCe; NdAlCe; CuAlCo; FeAlCo; ZnAlCo; NiAlCo; AgAlCo; CaAlCo; PtAlCo; PdAlCo; CdAlCo; MoAlCo; WAlCo; RuAlCo; SrAlCo; BaAlCo; NdAlCo; CuAlV; FeAlV; ZnAlV; NiAlV; AgAlV; CaAlV; PtAlV; PdAlV; CdAlV; MoAlV; WAlV; RuAlV; SrAlV; BaAlV; NdAlV; CuAlTi; FeAlTi; ZnAlTi; NiAlTi; AgAlTi; CaAlTi; PtAlTi; PdAlTi; CdAlTi; MoAlTi; WAlTi; RuAlTi; SrAlTi; BaAlTi; NdAlTi; CuAlHf; FeAlHf; ZnAlHf; NiAlHf; AgAlHf; CaAlHf; PtAlHf; PdAlHf; CdAlHf; MoAlHf; WAlHf; RuAlHf; SrAlHf; BaAlHf; NdAlHf; CuAlPr; FeAlPr; ZnAlPr; NiAlPr; AgAlPr; CaAlPr; PtAlPr; PdAlPr; CdAlPr; MoAlPr; WAlPr; RuAlPr; SrAlPr; BaAlPr; NdAlPr; CuAlLa; FeAlLa; ZnAlLa; NiAlLa; AgAlLa; CaAlLa; PtAlLa; PdAlLa; CdAlLa; MoAlLa; WAlLa; RuAlLa; SrAlLa; BaAlLa; and NdAlLa.

3. The catalysator element according to claim 2 , wherein at least one bivalent metal (M 2+ ) and said at least one trivalent metal (M 3+ ) are selected from the group of combinations consisting of CoAlCe; CoAlMn; CoAlFe; CoAlCo; CoAlV; CoAlTi; CoAlPr; CoAlLa; CuAlCe; FeAlCe; ZnAlCe; NiAlCe; AgAlCe; CaAlCe; PtAlCe; PdAlCe; CdAlCe; MoAlCe; RuAlCe; SrAlCe; BaAlCe; NdAlCe; PdAlMn; RuAlMn; CdAlCe; MoAlCe; WAlCe; RuAlCe; CuAlCo; FeAlCo; ZnAlCo; NiAlCo; CdAlCo; MoAlCo; WAlCo; RuAlCo; NdAlCo; CuAlPr; FeAlPr; NiAlPr; AgAlPr; CaAlPr; CdAlPr; CuAlLa; FeAlLa; NiAlLa; AgAlLa; CaAlLa; CdAlLa; MoAlLa; WAlLa; SrAlLa; BaAlLa; and NdAlLa.

4. The catalysator element according to claim 1 , wherein said calcined mixed metal oxide hydrotalcite-like compound is obtained by calcining a mixed metal oxide hydrotalcite-like compound comprising at least one bivalent metal (M 2+ ) and at least one trivalent metal (M 3+ ) at a temperature of between 200° C. to 600° C., for at least 1 hour.

5. The catalysator element according to claim 1 wherein said solid support is a metallic support or a ceramic support either zone coated or fully coated.

6. The catalysator element according to claim 1 , wherein said catalysator element is comprised in an exhaust system of a combustion engine or said catalysator element is comprised in a system that guides exhaust gases of a combustion engine.

7. The catalysator element according to claim 1 , wherein said calcined mixed metal oxide hydrotalcite-like compound has a catalytic surface area of at least 80 m 2 /g.

8. The catalysator element according to claim 1 , wherein said calcined mixed metal oxide hydrotalcite-like compound has an average pore diameter of at least 4 nm.

9. The catalysator element according to claim 1 , wherein said at least one bivalent metal (M 2+ ) has an atomic radius ranging from 0.3 {acute over (Å)} to 1.05 {acute over (Å)}, and wherein said at least one trivalent metal (M 3+ ) has an atomic radius ranging from 0.5 {acute over (Å)} to 1.1 {acute over (Å)}.

10. The catalysator element according to claim 1 , wherein said calcined mixed metal oxide hydrotalcite-like compound has an urea to NH 3 conversion rate of at least 50% at a temperature below 125° C.

11. The catalysator element according to claim 1 , wherein said calcined mixed metal oxide hydrotalcite-like compound has a total metal wt % ratio of M 2+ to M 3+ of between 0.05 and 0.8.

12. The catalysator element according to claim 1 , wherein said calcined mixed metal oxide hydrotalcite-like compound is comprised of a total metal wt % between 50 to 90 wt % of Co 2+ , between 4 to 30 wt % of Ce 3+ and between 2 to 30 wt % of Al 3+ .

13. The catalysator element according to claim 1 , wherein said calcined mixed metal oxide hydrotalcite-like compound is Co 6 Ce 0.8 Al 1.2 O 9 .

14. The catalysator element according to claim 1 wherein said solid support is selected from the list consisting of metal wiremesh, corrugated metal plates forming a metal substrate, ceramic mixers or other ceramic components guiding or influencing the flow, ceramic substrates, and substrates for SCR, SCRF or DPNR.

15. A method for the preparation of a calcined mixed metal oxide hydrotalcite-like compound according to claim 1 , wherein the method comprises;

a) mixing of at least one bivalent metal nitrite (M 2+ (NO 3 ) x ) with at least one trivalent metal nitrite (M 3+ (NO 3 ) x ) in an ammonium carbonate solution (NH 4 CO 3 ),

b) precipitating a mixed metal oxide hydrotalcite-like compound from the mixture,

c) recovering the mixed metal oxide hydrotalcite-like compound by drying, and calcining the dried mixed metal oxide hydrotalcite-like compound at between 200° C. to 600° C., for at least 1 hour.

16. The method according to claim 15 , wherein the calcined mixed metal oxide hydrotalcite-like compound is Co 6 Ce 0.8 Al 1.2 O 9 .

17. A calcined mixed metal oxide hydrotalcite-like compound obtainable by a method according to claim 15 .

18. An exhaust system for a combustion engine or a system that guides exhaust gases of a combustion engine comprising a catalysator element according to claim 1 .

19. A method for conversion of nitrogen oxides (NOx) in exhaust gasses comprising contacting said exhaust gasses with a catalysator element according to claim 1 during a sufficient time for allowing catalytic conversion of nitrogen oxides (NOx) comprising contacting urea with the catalysator element to generate NH 3 , followed by reduction of NOx with NH 3 over a SCR catalysator element.

20. A method for prevention of the formation of deposits including cyanuric acid downstream of an SCR catalyst or an SCRF catalyst including in the EGR system comprising contacting isocyanic acid with a catalysator element according to claim 1 thereby preventing the formation of cyanuric acid.

21. Method for conversion of urea (NH 2 ) 2 CO) into ammonia (NH 3 ) comprising contacting said urea with a catalysator element according to claim 1 during a sufficient time for allowing catalytic conversion of urea into ammonia.

22. Method of decomposing urea deposits in an exhaust system by contacting the deposits with a catalysator element according to claim 1 and by increasing the temperature over 140° C.