Method for manufacturing perfluorovinylethers

1. A process for the manufacture of a perfluorovinylether by hydrodehalogenation of a halofluoroether (HFE) having general formula (I-A) or (I-B):

R f O—CR f ′X—CR f ″R f ′″X′  (I-A)

wherein R f represents a C 1 -C 6 perfluoro(oxy)alkyl group; R f ′, R f ″ and R f ″′, equal to or different from each other, independently represent fluorine atoms or C 1 -C 5 perfluoro(oxy)alkyl groups; X and X′, equal to or different from each other, are independently selected from the group consisting of Cl, Br, and I;

wherein R f * and R f *′, equal to or different from each other, independently represent fluorine atoms or C 1 -C 3 perfluoro(oxy)alkyl groups;

Y 1 and Y 2 , equal to or different from each other, independently represent fluorine atoms or C 1 -C 3 perfluoroalkyl groups; X and X′ are the same as for formula (I-A); said process comprising contacting said halofluoroether (HFE) with hydrogen in the presence of a catalyst comprising at least one transition metal of group VIII B at a temperature of at most 340° C.,

wherein the process is carried out in gas-phase.

2. The process of claim 1 , wherein the halofluoroether (HFE) is a chlorofluoroether (HFE-1) having general formula (I-A), wherein X and X′, equal to or different from each other, are independently selected from the group consisting of Cl, Br, and I, with the proviso that at least one of X and X′ in said formula (I-A) is a chlorine atom.

3. The process of claim 1 , wherein the halofluoroether (HFE) is a chlorofluoroether (HFE-2) having general formula (II-A):

R f O—CR f ′Cl—CR f ″R f ′″Cl  (II-A)

wherein R f represents a C 1 -C 6 perfluoro(oxy)alkyl group; R f ′, R f ″ and R f ″′, equal to or different from each other, independently represent fluorine atoms or C 1 -C 5 perfluoro(oxy)alkyl groups.

4. The process of claim 1 , wherein the catalyst comprises at least one transition metal of group VIII B and an inert carrier.

5. The process of claim 4 , wherein the catalyst is a ruthenium catalyst supported on carbon.

6. The process of claim 5 , wherein the amount of ruthenium ranges from 0.5 wt. % to 1.5 wt. %.

7. The process of claim 1 , said process being carried out at a temperatures comprised between 190° C. and 340° C.

8. The process of claim 1 , wherein the hydrogen/halofluoroether (HFE) molar ratio is comprised between 0.8 and 4.

9. The process of claim 3 , wherein R f represents a C 1 -C 4 perfluoroalkyl group.

10. The process of claim 3 , wherein R f represents a C 1 -C 3 perfluoroalkyl group.

11. The process of claim 3 , wherein R f ′, R f ″ and R f ″′, equal to or different from each other, independently represent fluorine atoms or C 1 -C 3 perfluoroalkyl groups.

12. The process of claim 3 , wherein R f ′, R f ″ and R f ′″, equal to or different from each other, independently represent fluorine atoms or C 1 -C 2 perfluoroalkyl groups.

13. The process of claim 3 , wherein R f ′, R f ″ and R f ′″ represent fluorine atoms.

14. The process of claim 7 , being carried out at a temperature comprised between 200° C. and 340° C.

15. The process of claim 7 , being carried out at a temperature comprised between 210° C. and 320° C.

16. The process of claim 8 , wherein the hydrogen/halofluoroether (HFE) molar ratio is comprised between 0.8 and 3.

17. The process of claim 8 , wherein the hydrogen/halofluoroether (HFE) molar ratio is comprised between 0.8 and 2.