Increasing the lifetime of fuel cell catalysts

In this thesis, I discuss a novel idea of fuel cell catalyst regeneration to increase lifetime of the PEM fuel cell electrode/catalyst operation and, therefore, reduce the catalyst costs. As many of the catalyst degradation mechanisms are difficult to avoid, the regeneration is alternative option to prolong catalyst lifetime. In the thesis, I investigate fundamental aspects of Pt catalyst regeneration ex situ, which can be potentially applied in situ later on. The regeneration strategy consists of two steps: (i) Full or partial dissolution of coarsened Pt catalyst nanoparticles and (ii) Chemical or electrochemical redeposition of the dissolved Pt. I discuss dissolution aspects of Pt nanoparticles in mild and carbon-preserving conditions, which are essential for the subsequent redeposition of the nanoparticles on the same support and potential redeposition strategies. For the redeposition of Pt nanoparticles, we investigate electrodeposition technique and chemical reduction in a templated medium, such as microemulsions.Chemical EngineeringApplied Science