and carbon supported pt ru 40 20 by weight respectively each electrode was prepared by applying catalyst inks onto polytetrafluoroethylene ptfe impregnated carbon fiber paper substrates from toray industries the cathode and anode catalyst layers comprised approximately 0 7 0 75 mg pt cm 2 cathode and 0 3 mg pt cm 2 anode respectively nafion u00ae ionomer 1100 ew was also used in each catalyst layer however the amount of ionomer present in the cathode catalyst layers varied from cell to cell as indicated below each mea comprised a 25 u03bcm thick membrane made of a different ionomer suitable for this application grafoil u00ae graphite reactrant flow field plates with linear flow channels formed therein were located on either side of the meas thereby completing the fuel cell assembly the stack was then operated under typical dry automotive conditions at 60 u00b0 c and the voltage outputs at several current densities were determined in addition for two of the cells the start up time to reach 50 of nominal power output was determined from u2212 15 u00b0 c start up time for the other cell was not available these results are provided in the following table as is evident from the preceding table performance of the fuel cells is improved even under normal operating conditions at ionomer to catalyst wt values up to 33 67 the start up time for fuel cell c with a greater ionomer catalyst ratio in the cathode is less than that for fuel cell b electrodes comprising ionomer wt catalyst wt amounts up to 45 55 and even 55 45 are also expected to provide acceptable or improved results while particular elements embodiments and applications of the present invention have been shown and described it will be.