Verfahren zur Beschichtung einer Membran-Elektroden-Einheit mit Katalysator und Vorrichtung dafür

摘要

The invention relates to a method for electrochemically depositing a catalyst, especially a noble metal, from a precursor layer which is present on a membrane and in which the catalyst material is present in the form of salts that are soluble in the membrane material. According to the method, the membrane is surrounded by an atmosphere containing water vapour during the deposition process, this atmosphere ensuring the stability and ionic conductibility of the membrane. In contrast to methods used up until now, this prevents the soluble catalyst salt from being dissolved out the precursor layer. The method can be carried out in a simple device comprising a sealable vessel which can be advantageously tempered, a holder for receiving a membrane/precursor unit, a gas supply and electrical contacts.