Catalyst activation method

Patent metadata

Field	Value
Publication number	US-12357968-B2
Application number	US-202017418926-A
Country	US
Kind code	B2
Filing date	Jan 16, 2020
Priority date	Jan 17, 2019
Publication date	Jul 15, 2025
Grant date	Jul 15, 2025

Abstract

A method for activating a catalyst comprises the steps of: a) optionally drying the catalyst at a temperature of from 100° C. to 400° C.; b) treating the catalyst with a composition comprising HF at a temperature of from 0° C. to about 500° C.; c) treating the catalyst with a composition comprising an oxidant and optionally HF at a temperature of from about 100° C. to about 500° C.

First claim

The invention claimed is:

1. A method for activating a chromia catalyst comprising zinc oxide, the method comprising:
a) drying the catalyst at a temperature of from 100° C. to 400° C.;
b) treating the catalyst in a first activation step with a composition comprising HF at a temperature of from 100° C. to about 500° C.;
c) treating the catalyst in a second activation step with a composition comprising an oxidant and HF at a temperature of from about 100° C. to about 500° C.

2. The method according to claim 1 , wherein the oxidant is selected from the group consisting of air, oxygen (O 2 ), chlorine (Cl 2 ), chlorine monofluoride (ClF), nitrogen trifluoride (NF 3 ).

3. The method according to claim 1 , wherein the molar ratio of HF to oxidant is from 1:20 to 20:1.

4. The method according to claim 3 , wherein the molar ratio of HF to oxidant is from 15:1 to 1:3, or from 11:1 to 1:1.

5. The method according to claim 1 , wherein zinc oxide is present in the catalyst at a level of from 1% wt. to 10% wt., from 2% wt. to 8% wt., or from 3% wt. to 7% wt. based on the total weight of the catalyst.

6. The method according to claim 1 , wherein step (b) and/or (c) is carried out at a pressure of from 0.1 bara to 20 bara, or from 3 bara to 10 bara.

7. The method according to claim 1 , wherein step (b) and/or (c) is carried out over an extended period of time.

8. The method according to claim 1 , wherein step (b) and/or (c) is carried out at a temperature of from about 200° C. to about 500° C., or from about 250° C. to about 475° C.

9. The method according to claim 1 , wherein step (b) and/or (c) is conducted at a temperature of from about 300° C. to 460° C., or from about 310° C. to about 450° C.

10. The method for activating a catalyst according to claim 1 , wherein the zinc oxide is present in the catalyst at a level of from 1% wt. to 10% wt., wherein the catalyst has a total pore volume equal to or greater than 0.3 cm 3 /g and a mean pore diameter greater than or equal to 100 A, wherein the pore volume is measured using N 2 adsorption porosimetry and the mean pore diameter is measured using N 2 BET adsorption porosimetry.

11. The method according to claim 10 , further comprising a catalyst preparation process comprising:
preparing a metal salt solution and a hydroxide solution;
combining the solutions at a pH of greater than 7.5 in order to precipitate a metal hydroxide(s);
drying the precipitated metal hydroxide(s);
calcining the metal hydroxide(s) to form a metal oxide(s).

12. The method according to claim 10 , wherein the catalyst is amorphous, or from 0.1 to 50% by weight of the catalyst is in the form of one or more crystalline compounds of chromium and/or one or more crystalline compounds of zinc.

13. The method according to claim 10 , wherein the oxidant is selected from the group consisting of air, oxygen (O2), chlorine (Cl2), chlorine monofluoride (ClF), nitrogen trifluoride (NF3).

14. The method according to claim 10 , wherein the molar ratio of HF to oxidant is from 1:20 to 20:1, from 15:1 to 1:3, or from 11:1 to 1:1.

15. The method according to claim 10 , wherein step (b) and/or (c) is carried out at a pressure of from 0.1 bara to 20 bara, or from 3 bara to 10 bara.

16. The method according to claim 10 , wherein step (b) and/or (c) is carried out over an extended period of time.

17. The method according to claim 10 , wherein step (b) and/or (c) is carried out at a temperature of from about 200° C. to about 500° C., or from about 250° C. to about 475° C.

18. The method according to claim 17 , wherein step (b) and/or (c) is conducted at a temperature of from about 300° C. to 460° C., or from about 310° C. to about 450° C.

19. A method comprising a fluorination and/or hydrofluorination of a halogenated hydrocarbon in the presence of the catalyst prepared according to claim 1 .

20. The method according to claim 19 , wherein the halogenated hydrocarbon is a (hydro)haloalkene.

21. The method according to claim 20 , wherein the (hydro)haioalkene is a C 2-7 (hydro)haloalkene.

22. The method according to claim 21 , wherein the C 2-7 (hydro)haloalkene is a C 2-7 (hydro)chlorofluoroalkene.

23. The method according to claim 22 , wherein the C 2-7 (hydro)chlorofluoroalkene is 2-chloro-3,3,3-trifiuoropropene (1233xf).

24. A process for preparing a fluorinated hydrocarbon, the process comprising reacting an optionally halogenated hydrocarbon with hydrogen fluoride in the presence of the catalyst produced in accordance with the method of claim 1 , wherein the process is carried out in vapour phase.

Assignees

• Mexichem Fluor Sa De Cv

Inventors

• Sharratt Andrew
• Rees Claire

Classifications

• B01J2235/15

  X-ray diffraction · CPC title

• B01J35/653

  500-1000 nm · CPC title

• C07C17/07

  by addition of hydrogen halides · CPC title

• B01J37/06

  Washing {(B01J37/0009, B01J37/0018 take precedence)} · CPC title

• B01J35/50

  characterised by their shape or configuration · CPC title