Development of single-cell direct carbon monoxide fuel cells (DCMFCs)

Abstract

The ultimate objective of this project is to develop coal- and carbon-fueled fuel cells for portable applications. Since direct carbon fuel cells are nowhere near commercialization and the fuel gasification process requires a large amount of water (an undesirable characteristic for portable applications), the only remaining solution is to use the partial oxidation process to produce CO-rich gaseous fuel. This fuel then can be fed to direct carbon monoxide fuel cells (DCMFCs). These fuel cells require the development of CO-resistant anode catalysts. To develop these catalysts, direct alcohol fuel cells were used as the source of inspiration. Ten different catalysts were fabricated and tested. The results indicated that while the homemade Pt-Ru membrane-electrode assembly (MEA) outperformed the commercial Pt-Ru MEA it could not compete with the Pt-Sn MEA. While the performance of the MEAs with Pt-Ru-Ni, Pt-Ru-Sn-Ni, and Pt-Ru-Sn-Co was not satisfactory, the Pt-Ru-Sn-Co-W MEA achieved the best performance among all MEAs with Nafion® 117 membrane. The last MEA was made of the Pt-Sn anode catalyst and Nafion® 212 membrane and outperformed all other MEAs with a wide margin. The experiments demonstrated that the performance of the best-developed MEA was three times better than the performance of the commercial Pt-Ru MEA. This means the performance of DCMFCs can be significantly improved by developing a suitable anode electrocatalyst, using a thinner membrane, and operating at optimum conditions. These results are not only applicable for DCMFCs but also are very useful for other proton exchange membrane fuel cells (PEMFCs) operating with CO-containing fuels.