Catalytic hydrogenation of fluoroolefins, alpha- alumina supported palladium compositions and their use as hydrogenation catalysts

Patent metadata

Field	Value
Publication number	US-2023312443-A1
Application number	US-202318201892-A
Country	US
Kind code	A1
Filing date	May 25, 2023
Priority date	May 16, 2011
Publication date	Oct 5, 2023
Grant date	—

Abstract

A hydrogenation process is disclosed. The process involves reacting a fluoroolefin with H 2 in a reaction zone in the presence of a palladium catalyst to produce a hydrofluoroalkane product, wherein the palladium catalyst comprises palladium supported on a carrier wherein the palladium concentration is from about 0.001 wt % to about 0.2 wt % based on the total weight of the palladium and the carrier. Also disclosed is a palladium catalyst composition consisting essentially of palladium supported on α-Al 2 O 3 wherein the palladium concentration is from about 0.001 wt % to about 0.2 wt % based on the total weight of the palladium and the α-Al 2 O 3 . Also disclosed is a hydrogenation process comprising (a) passing a mixture comprising fluoroolefin and H 2 through a bed of palladium catalyst in a reaction zone wherein the palladium catalyst comprises palladium supported on a carrier; and (b) producing a hydrofluoroalkane product; characterized by: the palladium catalyst in the front of the bed having lower palladium concentration than the palladium catalyst in the back of the bed.

First claim

What is claimed is:

1 . A catalyst bed comprising a palladium catalyst supported on a carrier comprising α-Al 2 O 3 , the catalyst bed having a front and a back, wherein the palladium catalyst in the front of the catalyst bed has a first palladium concentration lower than a second palladium concentration of the palladium catalyst in the back of the catalyst bed.

2 . The catalyst bed according to claim 1 , wherein the first palladium concentration is from about 0.001 wt % to about 0.2 wt % based on the total weight of the palladium and the carrier in the front of the catalyst bed, and the second palladium concentration is from about 0.1 wt % to about 1 wt % based on the total weight of the palladium and the carrier in the back of the catalyst bed.

3 . The catalyst bed according to claim 1 , wherein the first palladium concentration is from about 0.001 wt % to about 0.08 wt % based on the total weight of the palladium and the carrier in the front of the catalyst bed, and the second palladium concentration is from about 0.2 wt % to about 0.8 wt % based on the total weight of the palladium and the carrier in the back of the catalyst bed.

4 . The catalyst bed according to claim 1 , wherein the first palladium concentration is from about 0.015 wt % to about 0.025 wt % based on the total weight of the palladium and the carrier in the front of the catalyst bed, and the second palladium concentration is from about 0.3 wt % to about 0.6 wt % based on the total weight of the palladium and the carrier in the back of the catalyst bed.

5 . The catalyst bed according to claim 1 , wherein a concentration of the palladium catalyst in the catalyst bed spatially increases continuously from a first concentration of palladium catalyst in the front of the bed to a second concentration of palladium catalyst in the back of the catalyst bed.

6 . The catalyst bed according to claim 1 further comprising hydrogen (H 2 ).

7 . The catalyst bed according to claim 6 further comprising at least one fluoroolefin having the formula C n H m F 2n-m , wherein n is an integer from 2 to 8 and m is an integer from 0 to 2n−1.

8 . The catalyst bed according to claim 1 further comprising at least one fluoroolefin having the formula C n H m F 2n-m , wherein n is an integer from 2 to 8 and m is an integer from 0 to 2n−1.

9 . The catalyst bed according to claim 8 , wherein n=3, m=2, and the at least one fluoroolefin is defined by the formula C 3 H 2 F 4 .

10 . The catalyst bed according to claim 9 , wherein the at least one fluoroolefin is selected from the group consisting of CF 3 CH═CHF and CF 3 CF═CH 2 .

11 . The catalyst bed according to claim 8 , wherein n=3 and m=0.

12 . The catalyst bed according to claim 8 , wherein n=3 and m=1.

13 . The catalyst bed according to claim 8 , wherein the at least one fluoroolefin is selected from the group consisting of CF 3 CF═CF 2 and CF 3 CF═CHF.

14 . The catalyst bed according to claim 8 further comprising at least one hydrofluoroalkane having the formula C n H m+2 F 2n-m .

15 . The catalyst bed according to claim 14 , wherein the molar ratio of the hydrofluoroalkane to the fluoroolefin is from 5:1 to 1:1 at the back of the catalyst bed.

Assignees

• Chemours Co Fc Llc

Inventors

• Cheung Patricia
• Lamarca Concetta

Classifications

• C07C17/354 Primary

  by hydrogenation · CPC title

• B01J21/04

  Alumina · CPC title

• B01J23/44

  Palladium · CPC title

• B01J35/1009

  Operations & Transport · mapped topic

• C07C21/18

  containing fluorine · CPC title