Laser-Induced Plasmon Excitation in Gold Nanoparticles to Evaporate Water and Increase Hydrogen Fuel Cell Efficiency

Flooding of recombined water in the cathode of polymer electrolyte fuel cells results in the necessity of excessive platinum (Pt) and reduced catalytic efficiency. Thermal sensitivity of the fuel cell membrane does not allow bulk heating of the cell as a means of combating flooding. However, we anticipate that flooding can be mitigated and the cell efficiency increased by the addition of targeted heating at the catalyst surface phonon decay of photon-excited plasmons in gold (Au) nanoparticle (NP) arrays imbedded within the cathode. We are currently using an Argon ion laser system to characterize the ability of plasmon heating in solid-state Au NP arrays to evaporate fluid from the array surface. We have expanded an energy balance to predict both the fluid evaporation rate and the effect of evaporative cooling on the local temperature profile of surfaces adjacent to the array. We compare the predicted thermal profiles using the model in its current state with those obtained experimentally. We believe the difference in equilibrium temperatures will be resolved by accounting in the model for mass change of the system due to the evaporating water.