Flame Aerosol Synthesis of Pt-Ru Anode Catalysts for Methanol Oxidation in Fuel Cells

摘要

In this contribution a novel method for preparation of unsupported PtRu catalysts for methanol oxidation is presented.Nanoparticles of PtRu are prepared as aerosol particles by flame spray pyrolysis and subsequently deposited directly on a gas diffusion layer (GDL).The comparison of performance of the flame synthesized PtRu (1:1) unsupported anode with a loading of 1.5 mg/cm2 with that of PtRu(1:1)/C (10 % metal,loading -1.5 mg/cm2) from E-TEK shows that both catalysts have similar onset potential (-210 mV) for methanol oxidation.However,the unsupported flame synthesized anode performs better than the anode prepared form supported E-TEK catalyst.Electrochemical impedance spectroscopy (EIS) has been used to observe the methanol oxidation on the anode catalyst.The EIS reveals that at 50°C and above the rate determining step is the oxidation of the surface adsorbed residues.EIS also shows improvement of methanol oxidation kinetics as the applied anodic potential is increased.