The Role of Tungsten Oxide in the Enhancement of Carbon Monoxide Tolerance of Platinum-Based Hydrogen Oxidation Catalysis.

Significant reductions in total cost of ownership can be realised by engineering PEM fuel cells to run on low-purity hydrogen. One of the main drawbacks of low-purity hydrogen fuels is the carbon monoxide fraction, which poisons platinum electrocatalysts and reduces the power output below useful levels. Platinum-tungsten oxide catalyst systems have previously shown high levels of CO tolerance in both ex situ and in situ investigations. In this work we explore the mechanism of enhanced tolerance using in situ electrochemical attenuated total reflection infrared (ATR-IR) and Raman spectroscopic methods, and investigate, using a mixture of Pt/C and WO3 powders, the role of the WV/WVI redox couple in the oxidation of adsorbed CO.