Regeneration of inactive and poisoned platinum catalysts

US4659683A · kind A · utility

Assignee

• BASF SE

Inventors

• Werner Biffar · Bischofswerda, DE
• Otto Hofstadt · Altrip, DE
• Klaus Kartte · Beindersheim, DE
• Erwin Thomas · Freinsheim, DE
• Franz-Josef Weiss · Schifferstadt, DE

Key dates

• Filing date: Mar 3, 1986
• Grant date: Apr 21, 1987
• Expiry date: Mar 3, 2006

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10S502/516
• WIPO field: Chemical engineering
• WIPO sector: Chemistry

Abstract

Noble metal catalyst, in particular platinum catalysts, which are applied on carriers and have become poisoned by metals as a result of being used for many years in the preparation of hydroxyl-ammonium salts by catalytic reduction of nitric oxide with hydrogen in an aqueous mineral acid are regenerated by a process in which the metallic impurities are dissolved using nitric acid or aqua regia, the solution is neutralized, the troublesome metals are precipitated from the neutralized solution by means of a selective precipitating reagent, and the purified platinum solution is reused for the preparation of the catalyst. Organic complexing agents which form insoluble or sparingly soluble complexes with the metallic impurities are preferably used as precipitating reagents.