Precious metal oxide catalyst for water electrolysis

US7976989B2 · kind B2 · utility

Assignee

• UMICORE AG & CO. KG · DE

Inventors

• Marco Lopez · Frankfurt, DE
• Andreas Schleunung · Großostheim, DE
• Peter Biberbach · Rodenbach, DE

Key dates

• Filing date: Oct 29, 2004
• Grant date: Jul 12, 2011
• Expiry date: Jul 31, 2027

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y02E60/50
• WIPO field: Chemical engineering
• WIPO sector: Chemistry

Abstract

The invention is directed to iridium oxide based catalysts for use as anode catalysts in PEM water electrolysis. The claimed composite catalyst materials comprise iridium oxide (IrO2) and optionally ruthenium oxide (RuO2) in combination with a high surface area inorganic oxide (for example TiO2, Al2O3, ZrO2 and mixtures thereof). The inorganic oxide has a BET surface area in the range of 50 to 400 m2/g, a water solubility of lower than 0.15 g/l and is present in a quantity of less than 20 wt. % based on the total weight of the catalyst. The claimed catalyst materials are characterised by a low oxygen overvoltage and long lifetime in water electrolysis. The catalysts are used in electrodes, catalyst-coated membranes and membrane-electrode-assemblies for PEM electrolyzers as well as in regenerative fuel cells (RFC), sensors, and other electrochemical devices.