Verfahren zur Herstellung eines Anodenkatalysators für Brennstoffzellen

Solutions of hexachloroplatinic acid and ruthenium chloride are added to a support material suspension. pH of the suspension is increased to 6.5-10 by adding an alkaline solution to precipitate sparingly soluble noble metal compounds. Organic carboxylic acid(s) and/or their salts are added to the suspension, and precipitated noble metal compounds are reduced to form a supported platinum-ruthenium catalyst. A support material is suspended in water to form a suspension. The suspension is heated at most up to solution boiling point. Solutions of hexachloroplatinic acid and ruthenium chloride are added to suspension while maintaining the same temperature and stirring. pH of the suspension is increased to 6.5-10 by adding an alkaline solution to precipitate hexachloroplatinic acid and ruthenium chloride in form of sparingly soluble noble metal compounds. Organic carboxylic acid(s) and/or their salts are added to the suspension, and precipitated noble metal compounds are reduced by adding reducing agents to form a supported platinum-ruthenium catalyst on a powdered support material. The catalyst is washed and dried. Independent claims are included for the following: (1) preparation of an unsupported platinum-ruthenium catalyst which involves heating solution comprising hexachloroplatinic acid and ruthenium chloride to a maximum of solutions boiling point. pH of the solution is increased to 6.5-10 by adding an alkaline solution to precipitate hexachloroplatinic acid and ruthenium chloride in form of sparingly soluble noble metal compounds, adding organic carboxylic acid(s) and/or their salts, reducing precipitated noble metal compounds by adding reducing agents to form the catalyst, washing and drying; (2) supported platinum-ruthenium catalyst; (3) unsupported platinum-ruthenium catalyst; (4) a membrane electrode assembly for fuel cells comprising the catalyst; and (5) method for using the catalyst in polymer electrolyte membrane or direct methanol fuel cells.