Preparation of anhydrous niobium and tantalum pentafluorides
AssigneeE. I. Du Pont de Nemours and Company
InventorMario J. Nappa
Life of this patent
Estimating the term…
Abstract
A method of producing an anhydrous niobium or tantalum pentafluoride involving reacting the corresponding pentoxide or oxyhalide with an excess of anhydrous hydrogen fluoride in the presence of a sufficient dehydrating agent (e.g., COCl.sub.2, SOCl.sub.2 or SO.sub.2 Cl.sub.2) to react with any water formed. Such a process is useful to produce a catalyticallyactive anhydrous niobium or tantalum pentafluoride in essentially a single liquid phase reaction step.
Claims12
A process for the preparation of an anhydrous niobium or tantalum pentafluoride comprising the steps of:
- (a) contacting niobium or tantalum pentoxide or oxyhalide in the presence of an excess of hydrogen fluoride at about 50.degree. C. to about 200.degree. C. for sufficient time to convert at least some of said niobium or tantalum pentoxide or oxyhalide to niobium or tantalum pentafluoride wherein said contacting is performed without pentafluoride addition and in the presence of an effective amount of a dehydrating agent to react with any water formed;
- and
- (b) recovering anhydrous niobium or tantalum pentafluoride.
A process for the preparation of an anhydrous niobium or tantalum pentafluoride consisting essentially of:
- (a) contacting niobium or tantalum pentoxide or oxyhalide in the presence of an excess of hydrogen fluoride to convert at least some of said niobium or tantalum pentoxide or oxyhalide to niobium or tantalum pentafluoride wherein said contacting is performed without pentafluoride addition and in the presence of an effective amount of a dehydrating agent to react with any water formed;
- and
- (b) recovering anhydrous niobium or tantalum pentafluoride.
A process for regenerating a catalyst which has been deactivated by an oxygen containing compound comprising the steps of:
- (a) providing a catalyst comprising at least one of niobium and tantalum pentafluorides;
- (b) contacting the catalyst in the presence of an excess of hydrogen fluoride at about 50.degree. C. to about 200.degree. C. for sufficient time to regenerate at least some of said niobium or tantalum pentafluoride wherein said contacting is performed without pentafluoride addition and in the presence of an effective amount of a dehydrating agent to react with any water formed;
- and
- (c) recovering regenerated anhydrous niobium or tantalum pentafluoride.
Dependencies are inferred from the claim text.