Process for the conversion of perfluoroalkanes, a catalyst for use therein and a method for its preparation

Abstract

A process for the decomposition of perfluoroalkanes comprises contacting a gaseous stream comprising the perfluoroalkanes with a catalyst comprising alumina. The alumina is prepared from one or more alumina sources, one of which is aluminum nitrate. The catalyst preferably comprises stabilizing agent, in particular zirconium oxide or cobalt, preferably both. The catalyst is prepared by forming a slurry of aluminum nitrate, optionally with one or more additional sources of alumina, in a suitable solvent, such as water. The resulting mixture is dried and calcined to yield the finished catalyst. The stabilizing agent or a precursor thereof may be included in the mixture or impregnated into the finished catalyst.

What is claimed is:  
     
         1 . A method for preparing a catalyst for use in the conversion of perfluoroalkanes, which method comprises forming a mixture comprising aluminum nitrate and a solvent, drying the mixture to remove the solvent and calcining the resulting material to yield a catalyst.  
     
     
         2 . A method according to  claim 1 , wherein the mixture comprises a further aluminum compound.  
     
     
         3 . A method according to  claim 2 , wherein the further aluminum compound is pseudoboehmite.  
     
     
         4 . A method according to  claim 1 , wherein the mixture further comprises a stabilizing agent or a precursor thereof.  
     
     
         5 . A method according to  claim 1 , further comprising impregnating the catalyst with a stabilizing agent or a precursor thereof.  
     
     
         6 . A method according to  claim 1 , wherein the calcination is conducted at a temperature of from 400 to 750° C.  
     
     
         7 . A method according to  claim 1 , wherein an acid is added to the mixture in order to peptize the alumina prior to drying.  
     
     
         8 . A method according to  claim 7 , wherein, following peptizing, the mixture is neutralized by the addition of a base.  
     
     
         9 . A catalyst for use in the decomposition of perfluoroalkanes, which catalyst comprises alumina prepared from aluminum nitrate.  
     
     
         10 . A catalyst according to  claim 9 , wherein the alumina has been prepared from at least two sources of alumina, at least one of which is aluminum nitrate.  
     
     
         11 . A catalyst according to  claim 9 , further comprising a stabilizing agent.  
     
     
         12 . A catalyst according to  claim 10 , wherein the stabilizing agent is selected from the group consisting of barium, calcium, cerium, phosphorus, chromium, cobalt, iron, lanthanum, magnesium, nickel, tin, titanium, zirconium and compounds thereof.  
     
     
         13 . A catalyst according to  claim 12 , comprising zirconium oxide and cobalt.