Process for dehydrochlorinating 1,1,1,2-tetrafluoro-2-chloropropane to 2,3,3,3-tetrafluoropropene in the presence of an alkali metal-doped magnesium oxyfluoride catalyst and methods for making the catalyst

1. A method, comprising the following steps:

(A) dissolving (i) an alkali metal halide in an effective amount of solvent or (ii) one or more of a hydroxide, an oxide, or a carbonate of an alkali metal in an aqueous solution of a hydrogen halide to form an alkali metal halide solution and

(B) admixing an effective amount of a bivalent metal oxyfluoride in the alkali metal halide solution to form a slurry.

2. The method of claim 1 , further comprising

(C) substantially removing the solvent from the slurry to form a solid residue;

(D) calcining the solid residue at conditions sufficient to effect substantial calcination; and

(E) grinding the calcined residue into a powder; and

(F) pelletizing the powder to form a solid catalyst composition.

3. The method of claim 1 , further comprising

(C) extruding the slurry to form an extrudate;

(D) substantially removing the solvent from the extrudate to form a solid residue; and

(E) optionally calcining the solid residue at conditions sufficient to effect substantial calcination.

4. The method of claim 2 , wherein substantially removing the solvent comprises the following steps: driving off a portion of the solvent from the slurry or the extrudate to form a paste and drying the paste to form a powder.

5. The method of claim 2 , wherein the solid residue is ground to form a finely divided powder; and wherein calcining is carried out at a temperature from about 300° C. to about 600° C.

6. The method of claim 2 , wherein the catalyst composition is represented by the following:

n wt. % MX/M′O y F z

wherein the alkali metal halide is represented by MX; wherein the bivalent metal oxyfluoride is represented by MX/M′O y F z ; wherein 0<y<1 and 0<z<2 and wherein y+z/2=1; wherein M is an alkali metal ion selected from the group consisting of Li + , Na + , K + , Rb + , and Cs + , X is a halogen ion selected from the group consisting of F − , Cl − , Br − , and I − , M′ is a bivalent metal ion; wherein n is a weight percentage of about 0.05% to about 50% MX based on the total weight of the MX and M′O y F z , and wherein y and z are the mole fractions of oxygen and fluorine in M′O y F z , respectively.

7. The method of claim 6 , the bivalent metal ion is selected from the group consisting of Mg 2+ , Ca 2+ , Sr 2+ , Ba 2+ , Ni 2+ , Fe 2+ , Co 2+ , Cu 2+ , and Zn 2+ , and wherein the halogen ion is selected from the group consisting of F − and Cl − .

8. The method of claim 6 , wherein the bivalent metal ion is Mg 2+ or Ni 2+ , wherein the alkali metal ion is Cs + or K + , and wherein the halogen ion is selected from the group consisting of F − and Cl − .

9. A method, comprising the following steps:

(A) dissolving (i) an alkali metal halide in an effective amount of solvent or (ii) one or more of a hydroxide, an oxide, or a carbonate of an alkali metal in an aqueous solution of a hydrogen halide to form an alkali metal halide solution and

(B) admixing one or more of a hydroxide, an oxide, or a carbonate of a bivalent metal in the alkali metal halide solution to form a slurry.

10. The method of claim 9 , further comprising

(C) substantially removing the solvent from the slurry to form a solid residue of the an alkali metal halide and the one or more of the hydroxide, the oxide, or the carbonate of the bivalent metal;

(D) calcining the solid residue at conditions sufficient to effect substantial calcination to form a calcined residue;

(E) grinding the calcined residue into a powder;

(F) pelletizing the powder to form pellets; and

(G) contacting the pellets with HF under conditions sufficient to convert the one or more of the hydroxide, the oxide, or the carbonate of the bivalent metal to a bivalent metal to a bivalent metal oxyfluoride.

11. The method of claim 10 , wherein removing the water comprises driving off a portion of the solvent from the slurry to form a paste and drying the paste to form the solid residue.

12. The method of claim 10 , wherein calcining takes place in N 2 flow for about 2 to about 8 hours at a temperature from about 300° C. to about 600° C.

13. The method of claim 10 , wherein the solid residue is ground to a finely divided powder.

14. The method of claim 10 , wherein the bivalent metal oxyfluoride is represented by the following:

n wt. % MX/M′O y F z

wherein the alkali metal halide is represented by MX; wherein the bivalent metal oxyfluoride is represented by MX/M′O y F z ; wherein 0<y<1 and 0<z<2 and wherein y+z/2=1; wherein M is an alkali metal ion selected from the group consisting of Li + , Na + , K + , Rb + , and Cs + , X is a halogen ion selected from the group consisting of F − , Cl − , Br − , and I − , M′ is a bivalent metal ion; wherein n is a weight percentage of about 0.05% to about 50% MX based on the total weight of the MX and M′O y F z , and wherein y and z are the mole fractions of oxygen and fluorine in M′O y F z , respectively.

15. The method of claim 14 , wherein the bivalent metal is selected from the group consisting of Mg 2+ , Ca 2+ , Sr 2+ , Ba 2+ , Ni 2+ , Fe 2+ , Co 2+ , Cu 2+ , and Zn 2+ , wherein the halide ion is selected from the group consisting of F − and Cl − .

16. The method of claim 14 , wherein the bivalent metal ion is Mg 2+ or Ni 2+ , wherein the alkali metal ion is Cs + or K + , and wherein the halogen ion is selected from the group consisting of F − and Cl − .

17. The method of claim 10 , wherein the pellets are contacted with HF for about 0.5 to about 20 hours at a temperature from about 300° C. to about 600° C.

18. The method of claim 9 , further comprising

(C) extruding the slurry to form an extrudate;

(D) substantially removing the solvent from the extrudate to form a solid residue of the an alkali metal halide and the one or more of the hydroxide, the oxide, or the carbonate of the bivalent metal;

(E) calcining the solid residue at conditions sufficient to effect substantial calcination to form a calcined residue;

(F) grinding the calcined residue into a powder;

(G) pelletizing the powder to form pellets; and

(H) contacting the pellets with HF under conditions sufficient to convert the one or more of the hydroxide, the oxide, or the carbonate of the bivalent metal to a bivalent metal to a bivalent metal oxyfluoride.