Copper-containing materials

• US 6,703,342 B1
• Filed: 09/18/2000
• Issued: 03/09/2004
• Est. Priority Date: 04/03/1998
• Status: Expired due to Term

• Current Assignee: Johnson Matthey PLC
• Original Assignee: Johnson Matthey PLC
• Inventors: Lok, Cornelis Martinus
• Primary Examiner(s): Silverman, Stanley S.
• Assistant Examiner(s): Strickland, Jonas N.
• Application Number:
  US09/664,556
• Time in Patent Office: 1,268 Days
• Field of Search: 502/439, 502/300, 502/344, 502/345, 502/346, 502/414, 502/415
• US Class Current: 502/346
• CPC Class Codes: B01J 20/0237 Compounds of Cu
• CPC Class Codes: B01J 20/0277 Carbonates of compounds other than those provided for in B01J20/043
• CPC Class Codes: B01J 20/06 comprising oxides or hydroxides of metals not provided for in group B01J20/04
• CPC Class Codes: B01J 20/08 comprising aluminium oxide or hydroxide; comprising bauxite
• CPC Class Codes: B01J 20/223 containing metals, e.g. organo-metallic compounds, coordination complexes
• CPC Class Codes: B01J 20/28004 Sorbent size or size distribution, e.g. particle size
• CPC Class Codes: B01J 20/28061 being in the range 100-500 m2/g
• CPC Class Codes: B01J 20/28073 being in the range 0.5-1.0 ml/g
• CPC Class Codes: B01J 20/28083 being in the range 2-50 nm, i.e. mesopores
• CPC Class Codes: B01J 20/3007 Moulding, shaping or extruding
• CPC Class Codes: B01J 20/3078 Thermal treatment, e.g. calcining or pyrolizing
• CPC Class Codes: B01J 20/3204 Inorganic carriers, supports or substrates
• CPC Class Codes: B01J 20/3236 containing metal, other than zeolites, e.g. oxides, hydroxides, sulphides or salts
• CPC Class Codes: B01J 21/04 Alumina
• CPC Class Codes: B01J 23/72 Copper
• CPC Class Codes: B01J 35/392 Metal surface area
• CPC Class Codes: B01J 37/0203 the impregnation liquid containing organic compounds
• CPC Class Codes: B01J 37/03 Precipitation; Co-precipitation

Abstract

Copper/alumina compositions for uses as e.g. catalysts are made by impregnating a porous transition alumina support with an aqueous solution of a copper ammine carbonate complex, draining off any excess of the impregnating solution, and then heating the impregnated support to a temperature above 80° C. to decompose the complex thereby depositing a basic copper carbonate compound on the surfaces of the pores of transition alumina support. After reduction, the composition has a high copper surface area, expressed per unit weight of copper in the composition.

Claims

1. A process for the manufacture of a composition comprising a copper compound supported on a transition alumina comprising impregnating a porous transition alumina support with on aqueous solution of a copper ammine carbonate complex having a pH in the range of 7 to 12, draining off any excess of the impregnating solution, and then heating the impregnated support to a temperature above 80°

C. to decompose the complex thereby depositing a basic copper carbonate compound on the surfaces of the pores of the transition alumina support in a highly dispersed form such that if the copper compound is reduced to metallic copper the composition would have a copper surface area above 40 m² per gram of copper.

2. A process according to claim 1 wherein the transition alumina is gamma or theta alumina.

3. A process according to claim 1 wherein the transition alumina support is preformed into shaped units having a minimum dimension of at least 1 nm.

4. A process according to claim 3, wherein the transition alumina units have maximum and minimum dimensions in the range 1 to 15 mm.

5. A process according to claim 1 wherein, after heating the impregnated support to decompose the copper ammine carbonate complex, the support is given one or more further impregnations of the copper ammine carbonate complex solution.

6. A process according to claim 1 wherein the impregnated support is heated to a temperature above 250°

C. to decompose the basic copper carbonate to copper oxide.

7. A process according to claim 1 wherein, after heating the impregnated support so decompose the copper ammine carbonate complex, the copper compound is reduced to elemental copper to give a composition having a copper surface area above 40 m² per gram of copper.

8. A process according to claim 1 wherein the amount of copper ammine carbonate complex employed is such that the copper to aluminium atomic ratio is in the range 0.025 to 0.5.

9. A process according to claim 1, wherein the aqueous solution of copper ammine carbonate complex has a pH in the range of 8 to 11.

10. A process according to claim 1, wherein the aqueous solution of copper ammine carbonate complex comprises the product obtained by dissolving basic copper carbonate in an aqueous solution of ammonium carbonate containing ammonium hydroxide.

11. A process according to claim 1, wherein the aqueous solution of copper ammine carbonate complex comprises 1 to 5 moles of the complex per liter of solution.

12. A process according to claim 1, wherein the aqueous solution of copper ammine carbonate complex comprises 2 to 4 moles of the complex per liter of solution.

13. A process according to claim 1, wherein the aqueous solution of copper ammine carbonate complex comprises 1.5 to 2.5 moles of the complex per liter of solution.