The Journal of Physical Chemistry B · 1998 · 66 citations · 29 references
Natural SciencesChemical EngineeringMaterials ScienceElectrochemical EngineeringElectrochemistryEnergy MaterialsCarbon-based Energy MaterialsElectrochemical CellsElectrode MaterialsElectrode-electrolyte InterfacesFuel Cell MaterialsFuel CellsAbsorption SpectraCarbon-based ElectrocatalystsElectrocatalystsFuel Cell CatalystsFuel Cell ElectrodesPolymer Electrolyte MembranesSupported ElectrocatalystsX-ray Absorption Spectroscopy
Two Pt−Ru/C catalysts, a commercial 20% Pt−10% Ru/C and a 10% Pt−5% Ru/C synthesized in house (YZU catalyst), were examined for the CO tolerance in polymer-electrolyte-membrane fuel cells (PEFCs). Both half-cell tests under 250 ppm of CO/H 2 and single-cell tests under 100 ppm of CO/H 2 showed that the YZU catalyst had smaller increase in the overvoltage at a given current. The platinum−ruthenium microstructures of these two electrocatalysts in the fabricated electrodes were characterized by X-ray absorption spectroscopy (EXAFS). EXAFS indicated that there was no Pt−Ru metal−metal interaction in the commercial catalyst; instead, only ruthenium oxide signals were observed. On the other hand, the YZU catalyst contains a Pt−Ru bimetallic interaction as indicated by the X-ray absorption spectra. It was considered that the Pt−Ru alloy structure has better CO tolerance than nonalloy Pt−Ru structure.
29