Catalyst and method for its preparation
A catalyst including gold, or a compound thereof, and sulphur, a compound of sulphur, trichloroisocyanuric acid or a metal dichloroisocyanurate on a support, together with a process for manufacturing the catalyst and its use in a chemical process are described.
1. A catalyst comprising a complex of gold with a sulphur-containing ligand on a support.
2. The catalyst according to claim 1 , wherein said sulphur-containing ligand is an oxidizing ligand containing sulphur in a positive oxidation state.
3. The catalyst according to claim 2 , wherein said sulphur-containing ligand is derived from a compound selected from the group consisting of a sulphonate, a thiosulphate, a thiocyanate, thiourea, thionyl chloride, thiopropionic acid and thiomalic acid.
4. The catalyst according to claim 1 , comprising from 0.005-15%, by weight, of sulphur.
5. The catalyst according to claim 1 , containing from 0.01-10% of gold, by weight based on the weight of the total catalyst.
6. The catalyst according to claim 1 , wherein said support comprises carbon.
7. The catalyst according to claim 1 , wherein said support comprises a metal oxide.
8. The catalyst according to claim 1 , wherein said support is in the form of a powder, granulate or shaped unit.
9. The catalyst according to claim 1 , wherein at least some of the gold is in a positive oxidation state.
10. The catalyst according to claim 1 , further comprising a metal or a compound of a metal selected from the group consisting of cobalt, copper, lanthanum, cerium, lithium, sodium, potassium, rubidium, caesium, magnesium, calcium, strontium and barium.
11. A method of manufacturing the catalyst according to claim 1 , comprising:
impregnating a catalyst support with a solution of gold or a compound thereof and a solution of a sulphur-containing ligand to form a gold complex, followed by
drying the impregnated support.
12. A chemical process comprising reacting at least one chemical substrate in the presence of the catalyst according to claim 1 .
13. The chemical process according to claim 12 , comprising the oxidation of said chemical substrate.
14. A process for the hydrochlorination of an alkyne comprising reacting said alkyne with HCl in the presence of the catalyst according to claim 1 .
15. The process according to claim 14 , wherein the sulphur is present in the form of elemental sulphur or a sulphur compound which is not a ligand complexed to the gold.
16. The process according to claim 14 , wherein the catalyst comprises from 0.005-10%, by weight, of sulphur.
17. The process according to claim 14 , wherein the catalyst comprises from 0.01-10% by weight of gold.
18. The process according to claim 14 , wherein the catalyst comprises a complex of gold with a sulphur-containing ligand on a support.
19. The process for the hydrochlorination of an alkyne, according to claim 14 , comprising a step of treating said catalyst with hydrogen chloride in the absence of acetylene.
20. A process for the hydrochlorination of an alkyne comprising reacting said alkyne with HCl in the presence of the catalyst according to claim 3 .