Preparation of hydroxylammonium salts
AssigneeBASF SE
InventorsHugo Fuchs, Josef Ritz, Erwin Thomas, Franz-Josef Weiss
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Abstract
Hydroxylammonium salts are prepared by catalytic reduction of nitrogen monoxide with hydrogen at elevated temperature in a dilute aqueous solution of a mineral acid in the presence, in suspension, of a supported platinum catalyst obtainable by precipitating metallic platinum from an aqueous platinum solution onto a support by means of a reducing agent in the presence of an organic chelating agent and partially poisoned with sulfur.
Claims5
In a process for preparing a hydroxylammonium salt by the catalytic reduction of nitrogen monoxide with hydrogen at elevated temperature in a dilute aqueous solution of a mineral acid and in the presence, in suspension, of a supported platinum catalyst, the improvement which comprises:
- preparing said supported platinum catalyst, by
- (a) adding to an aqueous solution of a platinum salt containing a suspended support
- (i) a sulfur compound selected from the group consisting of alkali metal dithionite, alkali metal sulfide, sulfurous acid, alkali metal sulfite and derivatives of sulfoxylic acid with formaldehyde, and
- (ii) an aminopolycarboxylic acid,
- (b) precipitating platinum on the support from said aqueous solution by adding a reducing agent, and
- (c) separating the supported platinum catalyst from the aqueous solution containing said aminopolycarboxylic acid.
Dependencies are inferred from the claim text.