method for deposition of, in particular, of one or more metals in the platinum group or the existing catalyst alloys in a porous gas diffusionselektrode

摘要

1,154,374. Fuel cell electrodes. INTERNATIONAL NICKEL Ltd. 18 Aug., 1966 [24 Aug., 1965], No. 36343/65. Heading H1B. [Also in Division C7] A catalyst e.g. a Pt group metal, Ag, Ni or Co is deposited at a predetermined distance from a face of a porous gas diffusion electrode of e.g. Ni, Ti, Ta, stainless steel, carbon or porous PVC coated with Ag. The deposition at the required level is effected by chemical or physical interaction between gas and liquid phases or between two immiscible liquid phases applied one to each side of the electrode. The reaction may take place while the electrode is operating in a cell, and the electrode may be of dual porosity. Examples are: (1) reducing solutions of Ag, Pt or Pd e.g. silver nitrate, hexahydroxyplatinate or palladonitrite by hydrogen with or without a trace of formaldehyde vapour; and (2) evaporating a solution of dichloro-bisdi - n - butyl sulphide Pd in n - heptane, using a stream of air, removing excess solution and then heating at 350‹ C. to convert to Pd.