A method of operating a fuel
cell at an
operating temperature below about 150 degrees Celsius, wherein the fuel
cell has an
anode and a
cathode with an
electrolyte interposed therebetween, the
cathode having at least one surface in contact with a
cathode chamber having a gas inlet and a gas outlet, and the
anode in contact with an
anode chamber having a gas inlet and a gas outlet, and the
electrolyte containing less than about 500 ppm of a catalyst capable of enhancing the formation of radicals from
hydrogen peroxide. The method includes the steps of applying a fuel to the anode chamber; applying an oxidant to the cathode chamber; and controlling the amount of water supplied to the anode chamber and the cathode chamber such that
water vapor pressure is sub-saturated at the
operating temperature at the gas outlet of the cathode chamber. Also disclosed is an apparatus comprising sensors to measure outlet
relative humidity of the gas outlets of a fuel
cell and a means to control the
relative humidity on the gas inlets of a fuel cell, such that the apparatus can control the
relative humidity of the gas inlets to maintain an average relative
humidity in the fuel cell of less than 100%.