Electrocatalysis of CO Tolerance by Carbon-Supported PtMo Electrocatalysts in PEMFCs

This paper is a full version of an earlier short communication, where significantly higher (up to threefold) CO tolerance was reported for PtMo/C (atomic ratio, Pt:Mo, 3:1) relative to the current state-of-the-art PtRu/C (1:1) in a proton exchange membrane fuel cell (PEMFC) under standard operating conditions (85°C, 100% humidification, with pm We report significantly different behavior for PtMo/C in contrast to PtRu/C, wherein there is negligible variation in CO tolerance (100 ppm CO in with variations in alloying compositions (Pt:Mo, 1:1 to 5:1). Further, in contrast to Pt/C and PtRu/C, significantly lower variations in overpotential losses is observed for PtMo/C as a function of temperature (55–115°C) and CO concentrations (5–100 ppm, balance In addition, excellent long-term stability is reported for PtMo/C (1:1) under steady-state conditions (constant potential conditions at 0.6 V) for a total duration of 1500 h, with anode gas composition varied between pure and those with 100 ppm CO, with or without the presence of other reformate gases (primarily and These are discussed in the context of detailed physicochemical characterization of the nanoparticles using a combination of X-ray diffraction, transmission electron microscopy, and in situ synchrotron X-ray absorption spectroscopy. © 2004 The Electrochemical Society. All rights reserved.