as platinum palladium ruthenium chromium iridium rhodium and alloys thereof typically having a thickness of less than about 1 mil referring to fig2 a schematic of a fuel cell system 20 which utilizes an electrochemical hydrogen purifier liquid or gaseous hydrocarbon fuel 22 together with water 25 converts to hydrogen gas and carbon based byproducts in a reformer 24 the contaminated hydrogen gas stream 102 enters purifier 101 where the carbon contaminants such as carbon dioxide and carbon monoxide are removed from the hydrogen stream and if desired the pressure of the hydrogen stream is increased accordingly while the carbon contaminant stream 104 vents from the purifier 101 the purified pressurized hydrogen gas 109 enters fuel cell stack 28 along with an oxidant 26 normally air within the fuel cell 28 a controlled recombination of hydrogen and oxygen occurs to produce electric power 29 the benefit of the purification system 101 is that the purified hydrogen gas 109 used in fuel cell 28 enhances the performance and reliability while reducing maintenance requirements now with reference to fig3 a schematic representation of fuel processor module 30 is shown having a membrane 108 an anode 103 and a cathode 107 screen packages 32 35 37 are sandwiched between the anode 103 and separator plate 34 cathode 107 and separator plate 36 and separator plates 36 and 38 respectively screens 32 35 collect current from the anode 103 and cathode 107 while screen 37 serves as a fluids distributor of the coolant water important factors in effectively purifying the hydrogen stream 102 include the voltage applied across the anode membrane cathode assembly the flow rate of the contaminated hydrogen stream 102 and the hydrogen residence time on the anode 103 during operation the power source.