Metal Nitride Support Boosts Fuel-Cell Catalyst Performance

Fuel cells have been used for decades to supply electricity for space and terrestrial applications. Yet these electrochemical devices, which have been eyed for automotive use, have not been broadly commercialized in part because of durability problems and high cost. In particular, normal fuel-cell operation corrodes and oxidizes the carbon materials typically used as catalyst supports, leading to catalyst degradation and poor device performance. Metal nitrides have been studied as replacement supports, but they don’t always tolerate the acidic conditions required for some fuels. A Cornell University team led by Francis J. DiSalvo now reports that a titanium chromium nitride material appears to overcome those problems (ACS Nano 2014, DOI: 10.1021/nn5014337). The researchers found that palladium-silver nanoparticles supported on a highly porous Ti_0.5Cr_0.5N network serves as an active and stable catalyst system in acidic and alkaline media across the typical range of fuel-cell voltages. Tests using methanol and formic acid solutions­­—alkaline and acidic, respectively—show that the PdAg/Ti_0.5Cr_0.5N system remains more active and durable than the same catalyst or a palladium nanoparticle catalyst supported on standard carbon materials.