Abstract: Methods and kits for removing contaminants from fuel cells are disclosed. The methods include passing a removal substance through a flow channel in the cell, where the substance is selected to remove the contaminant. The contaminants can be, e.g., metallic ions or organic compounds, and the removal substance can be, e.g., acidic or alkaline solutions, chelating agents, or oxidants.

Abstract: The invention relates to an enthalpy recovery fuel cell system. Water leaving the fuel cell in the cathode gas output stream is transferred to the cathode gas input stream. The dew point of the input stream of the cathode gas is about the same as the temperature of the leading edge of the active area of the solid electrolyte, such as a proton exchange membrane. The temperature differential across the fuel cell is about the same as the difference in the dew points of the cathode gas entering the fuel cell and the cathode gas exiting the fuel cell.

Abstract: The invention relates to a fuel cell system having membranes that are used to humidify reactant gases. The membranes effectively prevent contamination of the reactant gases during humidification. The membranes can be used to purify the reactant gases during humidification.