Nanoimprinted electrodes for micro-fuel cell applications

Nanoimprint lithography (NIL) was used to fabricate electrodes with high specific Pt surface areas for use in micro-fuel cell devices. The Pt catalyst structures were characterized electrochemically using cyclic voltammetry and were found to have electrochemical active surface areas (EAS) ranging from 0.8 to 1.5 m2 g−1 Pt. These NIL catalyst structures were tested in fuel cell membrane electrode assemblies (MEA) by directly embossing a Nafion 117 membrane. The features of the mold were successfully transferred to the Nafion and a 7.5 nm thin film of Pt was deposited at a wide angle to form the anode catalyst layer. The resulting MEA yielded a very high Pt utilization of 15,375 mW mg−1 Pt compared to conventionally prepared MEAs (820 mW mg−1 Pt). Embossing pattern transfer was also demonstrated for spin casted Nafion films which could be used for new applications.