Chromium oxyfluoride catalysts having high fluorination activity

Patent metadata

Field	Value
Publication number	US-10363549-B2
Application number	US-201615748246-A
Country	US
Kind code	B2
Filing date	Aug 3, 2016
Priority date	Aug 5, 2015
Publication date	Jul 30, 2019
Grant date	Jul 30, 2019

Abstract

X-Ray photoelectron spectroscopy (XPS) is used to assess or predict the catalytic activity of a chromium oxyfluoride catalyst in a reaction wherein a chlorinated compound is converted to a fluorinated compound.

First claim

What is claimed is:

1. A chromium oxyfluoride catalyst active for fluorination of a chlorinated compound, wherein the chromium oxyfluoride catalyst is comprised of a first chromium species and a second chromium species, wherein the first chromium species exhibits a first X-ray photoelectron spectroscopy (XPS) chromium Cr 2p 3/2 peak between 576.9 eV+/−0.2 eV and 578.0 eV+/−0.2 eV and the second chromium species exhibits a second X-ray photoelectron spectroscopy (XPS) chromium Cr 2p 3/2 peak between 580.0 eV+/−0.2 eV and 581.4 eV+/−0.2 eV and wherein the intensity of the second XPS chromium peak is greater than the intensity of the first XPS chromium peak.

2. The chromium oxyfluoride catalyst of claim 1 , wherein the chromium oxyfluoride catalyst is a supported catalyst.

3. The chromium oxyfluoride catalyst of claim 1 , wherein the chromium oxyfluoride catalyst is a catalyst supported on an aluminum-containing support.

4. The chromium oxyfluoride catalyst of claim 2 , wherein the ratio of the intensity of the second XPS chromium peak to the intensity of the first XPS chromium peak is greater than 2.5.

5. The chromium oxyfluoride catalyst of claim 1 , wherein the chromium oxyfluoride catalyst is a bulk catalyst.

6. The chromium oxyfluoride catalyst of claim 5 , wherein the ratio of the intensity of the second XPS chromium peak to the intensity of the first XPS chromium peak is greater than 8.0.

7. The chromium oxyfluoride catalyst of claim 1 , wherein the chromium oxyfluoride catalyst is comprised of a first oxygen species and a second oxygen species, wherein the first oxygen species exhibits a first X-ray photoelectron spectroscopy (XPS) oxygen O 1 s peak between 530.3 eV±0.2 eV and 531.6 eV±0.2 eV and the second oxygen species exhibits a second X-ray photoelectron spectroscopy (XPS) oxygen O 1 s peak between 532.4 eV±0.2 eV and 532.8 eV±0.2 eV and wherein the intensity of the second XPS oxygen peak is greater than the intensity of the first XPS oxygen peak.

8. The chromium oxyfluoride catalyst of claim 7 , wherein the ratio of the intensity of the second XPS oxygen O 1 s peak to the intensity of the first XPS oxygen O 1 s peak is greater than 2.

9. The chromium oxyfluoride catalyst of claim 1 , wherein the energy shift between the first XPS chromium Cr 2p 3/2 peak and the second XPS chromium Cr 2p 3/2 peak is 3.3 eV±1.7 eV.

10. The chromium oxyfluoride catalyst of claim 1 , wherein the chromium oxyfluoride catalyst is modified with at least one metal selected from the group consisting of Zn, Co, Ni, Mn, Mg and combinations thereof.

11. A method of assessing the activity of a chromium oxyfluoride catalyst for fluorination of a chlorinated compound, wherein the method comprises analyzing the chromium oxyfluoride catalyst by X-ray photoelectron spectroscopy (XPS) to measure the relative intensities of a first XPS chromium Cr 2p 3/2 peak between 576.9 eV+/−0.2 eV and 578.0 eV+/−0.2 eV associated with a first chromium species and a second XPS chromium Cr 2p 3/2 peak between 580.0 eV+/−0.2 eV and 581.4 eV+/−0.2 eV associated with a second chromium species.

12. A method of fluorinating a chlorinated compound, comprising contacting the chlorinated compound and hydrogen fluoride in gas phase in the presence of a chromium oxyfluoride catalyst in accordance with claim 1 to produce a fluorinated compound.

13. The method of claim 12 , wherein the chlorinated compound is 1,1,2,3-tetrachloropropene and the fluorinated compound is HFO-1234yf or the chlorinated compound is 2-chloro-3,3,3-trifluoropropene and the fluorinated compound is HFO-1233xf.

14. A method of making a chromium oxyfluoride catalyst active for fluorination of a chlorinated compound, wherein the method comprises preparing the chromium oxyfluoride catalyst under conditions effective to provide a chromium oxyfluoride catalyst wherein the intensity of a first XPS chromium Cr 2p 3/2 peak between 576.9 eV+/−0.2 eV and 578.0 eV+/−0.2 eV associated with a first chromium species in the chromium oxyfluoride catalyst is less than the intensity of a second XPS chromium Cr 2p 3/2 peak between 580.0 eV+/−0.2 eV and 581.4 eV+/−0.2 eV associated with a second chromium species.

15. A method of making a chromium oxyfluoride catalyst active for fluorination of a chlorinated compound, comprising the following stages, in succession: a) an unactivated catalyst preparation stage, wherein an unactivated chromium oxyfluoride catalyst is prepared; b) a first activation stage, wherein the unactivated catalyst is subjected to activation conditions to obtain a first activated chromium oxyfluoride catalyst; c) a catalyst evaluation stage, wherein the first activated chromium oxyfluoride catalyst is analyzed by XPS to measure the relative intensities of a first XPS chromium Cr 2p 3/2 peak between 576.9 eV+/−0.2 eV and 578.0 eV+/−0.2 eV and a second XPS chromium Cr 2p 3/2 peak between 580.0 eV+/−0.2 eV and 581.4 eV+/−0.2 eV; and either d1) a second activation stage, wherein the first activated chromium oxyfluoride catalyst is further subjected to activation conditions to obtain a second activated chromium oxyfluoride catalyst, if the intensity of the first XPS chromium Cr 2p 3/2 peak is not less than the intensity of the second XPS chromium Cr 2p 3/2 peak or d2) a reaction stage wherein a chlorinated compound is contacted with hydrogen fluoride in gas phase in the presence of the first activated chromium oxyfluoride catalyst to produce a fluorinated compound, if the intensity of the first XPS chromium Cr 2p 3/2 peak is less than the intensity of the second XPS chromium Cr 2p 3/2 peak.

16. A method of regenerating a spent chromium oxyfluoride catalyst improve its activity for fluorination of a chlorinated compound, wherein the method comprises regenerating the chromium oxyfluoride catalyst under conditions effective to provide a chromium oxyfluoride catalyst wherein the intensity of a first XPS chromium Cr 2p 3/2 peak between 576.9 eV+/−0.2 eV and 578.0 eV+/−0.2 eV associated with a first chromium species present in the chromium oxyfluoride catalyst is less than the intensity of a second XPS chromium Cr 2p 3/2 peak between 580.0 eV+/−0.2 eV and 581.4 eV+/−0.2 eV associated with a second chromium species.

17. A method, comprising the following steps in succession: a) a first reaction stage wherein a chlorinated compound is contacted with hydrogen fluoride in gas phase in the presence of a chromium oxyfluoride catalyst to produce a fluorinated compound, wherein the first reaction stage is carried out for a length of time sufficient to cause the activity of the chromium oxyfluoride catalyst to fall below a selected value; b) a first reactivation stage, wherein the chromium oxyfluoride catalyst is subjected to reactivation conditions to obtain a first reactivated chromium oxyfluoride catalyst; c) a catalyst evaluation stage, wherein the first reactivated chromium oxyfluoride catalyst is analyzed by XPS to measure the relative intensities of a first XPS chromium Cr 2p 3/2 peak between 576.9 eV+/−0.2 eV and 578.0 eV+/−0.2 eV and a second XPS chromium Cr 2p 3/2 peak between 580.0 eV+/−0.2 eV and 581.4 eV+/−0.2 eV; and either d1) a second reactivation stage, wherein the chromium oxyfluoride catalyst is further subjected to reactivation conditions to obtain a second reactivated chromium oxyfluoride catalyst, if the intensity of the first XPS chromium Cr 2p 3/2 peak is not less than the intensity of the second XPS chromium Cr 2p 3/2 peak or d2) a second reaction stage wherein a chlorinated compound is contacted with hydrogen fluoride in gas phase in the presence of the first reac

Assignees

• Arkema Inc

Inventors

• Ricou Pierre
• Doucet Nicolas
• Pigamo Anne Marie

Classifications

• B01J21/04

  Alumina · CPC title

• C07C17/206 Primary

  the other compound being HX · CPC title

• B01J27/12 Primary

  Fluorides · CPC title

• B01J27/32

  of catalysts comprising compounds of halogens · CPC title

• B01J27/132

  with chromium, molybdenum, tungsten or polonium · CPC title