Research Of The Oxygen Enrichment Of Ag In The Proton Exchange Membrane Fuel Cell Catalyst Layer

Generally speaking, air is used as the oxidant of Proton Exchange Membrane Fuel Cell on the land. But air is mainly consisted of nitrogen, and if a higher air utilization or a higher current density of the fuel cell is needed, with the lack of oxygen, a "Nitrogen Blanket" will be formed which cover the catalyst layer which will also prevent the catalyst layer from getting touch with oxygen. In the cathode, before oxygen getting touch with the Pt/C catalyst, most oxygen molecular should firstly get across a bed of per-fluorinated sulphur acid resin (PFSA). Ag has the ability to enrich oxygen, so that if Ag is added into the PFSA, it will facilitate the transport of oxygen, the efficiency of the PEMFC will be increased.In the paper, ion-exchange method is used to introduce silver into the cathode electrode catalyst layer of PEMFC, and then the oxygen enrichment function of Ag-resin and the performance of Ag-electrode on the cathode side of PEMFC is tested, at the same time, the influence of the concentration of AgNO₃, cell temperature, relative humidity of gas inlet and air flux conditions are also investigated. Results show that: Firstly, in the resin, silver has an obvious ability of facilitating oxygen transport, and as the rise of the fuel cell temperature, both of the oxygen enrichment function of Ag-resin and the performance of Ag-electrode on the cathode side of PEMFC are enhanced. For the mass of silver carried in the resin or the cathode catalyst layer, both of the tests indicate that the best loading of Ag is 0.1 wt%.