Electrooxidation of Formic Acid Over Pt Supported on Carbon Nanotubes

Formic acid has been recently identified as a promising energy source for low temperature PEM fuel cells. It can be obtained from the environment (ants, fruits), it has a high energy density, a lower crossover across NafionŽ than methanol, and employs a more CO tolerant catalysts for oxidation. This work presents the benefits of employing multi-walled carbon nanotubes as supports for formic acid oxidation catalysts. Two significant benefits are observed when mixed acid functionalized multi-walled nanotubes (FMWNT) are used as supports instead of Vulcan XC 72 for platinum catalyst. This includes:

1. A 50% increase in formic acid electrooxidation.

2. A shift in CO oxidation potential to lower values by ~50 mV.

The results presented here not only demonstrates the feasibility of using multi-walled nanotubes as supports for formic acid oxidation catalyst, but also shows a more energy efficient way to oxidize formic acid. These results can be the basis for evaluating other catalysts over nanotubes for formic acid oxidation. These results also assume a broader significance because of the rapidly growing commercial interest on formic acid as a benign portable energy source for different applications such as communication devices (cell phones) and data processors (laptops).