CO-tolerant operation ofplatinum-loaded

Biomass isa greenenergysource, whichcanbe converted tohydrogen richgas.Ifthis gasisusedasfeedstock foraPEM fuel cell, itispossible toconvert biomass toelectricity inanenvironmental friendly way.A disadvantage ofaPEM fuel cell isthatplatinum, whichisusedascatalyst tospeedupthe anodereaction, isagoodadsorbent forCO.Carbonmonoxide willadheretotheplatinum surface blocking thecatalyst for hydrogen oxidation. Inordertocleanthecatalyst, oxygencan beaddedtothefuel stream. Byapplying negative voltage pulses tothecellterminals, existing watercangetelectrolyzed. This results intrace amountsofoxygen intheanodechannel. Measurements performed onapoisoned fuelcell stackhave beenconducted. Theresults ofthemeasurements showthatthe poisoned cells regenerate after anegative pulse. Byoptimizing the pulse amplitude, repetition timeanddutycycle, thefuel cell used isCO-tolerant forgasses containing 50ppmCO.Furthermore, celloscillations, probably related toself-oxidation ofcarbon monoxide, areobserved, whichisremarkable forPEM fuel cells withpureplatinum loaded catalysts.