Fuel‑Cell Catalysts Tolerate CO

A novel nanoparticulate platinum catalyst outperforms commercial platinum catalysts in terms of stability, oxidation activity, and resistance to carbon monoxide poisoning, according to chemists at Cornell University (J. Am. Chem. Soc., DOI: 10.1021/ja102931d). The study could lead to longer lasting and better performing catalysts for proton-exchange-membrane fuel cells, which in turn could hasten widespread deployment of these electrochemical power generators in transportation and portable electronics applications. Carbon-supported platinum’s exceptional knack for catalyzing hydrogen oxidation is quickly curtailed by low parts-per-million levels of CO, which poison the catalyst surface. The leading solution to the problem calls for formulating Pt/C catalysts with ruthenium—but even those catalysts are not durable enough for large-scale commercialization. Deli Wang, Chinmayee V. Subban, Héctor D. Abruña, and coworkers have shown that depositing low levels of platinum on tungsten-substituted titania (Ti_0.7W_0.3O₂) yields a highly active hydrogen-oxidation catalyst that resists CO poisoning better than commercial Pt/C and PtRu/C catalysts. The enhanced resistance is due to titania’s and tungsten’s facility for oxidizing CO, the team explains.