METHODS FOR CONTAMINANT REMOVAL FROM POLYMER ELECTROLYTE MEMBRANE FUEL CELLS AND FUEL CELL STACKS

Methods for removing contaminants from a polymer electrolyte membrane (PEM) fuel cell or fuel cell stack are provided. The methods are conducted without the need for disassembly of the cell or stack, and can be performed as throughout the lifetime of the cell or stack for prevention of performance loss. The methods include introducing an acidic solution to a first electrode side of a membrane electrode assembly and hydrogen gas to a second electrode side of the membrane electrode assembly and applying a hydrogen pumping current across. Thereafter, the acidic solution is removed by supplying reactant gases to the electrodes at relative humidity above saturation.