Performance enhancement of polymer electrolyte membrane fuel cell by PtCo₃ nanoporous film as high mass-specific power density catalyst using laser deposition and processing

This study demonstrates the performance of polymer electrolyte membrane fuel cell (PEMFC) can be significantly enhanced with laser deposited and processed PtCo₃ nanoporous film as the catalyst layer. The PtCo₃ nanoporous film is fabricated by first depositing a thin film of stacked PtCo₃ nanoparticles on gas diffusion layer using pulsed laser deposition and then subjecting the film to scanning continuous-wave laser processing. The heating by the scanning laser beam increases electrochemical surface area substantially, which could be ascribed to formation of Pt skin on each nanoparticle via Pt surface segregation. Furthermore, the durability of the catalyst under accelerated degradation test is greatly enhanced, which may be attributed to inhibition of Co leaching by the Pt skin and strengthening of the contacts between nanoparticles caused by concomitant sintering effect. Application of such catalyst to the cathode of a PEMFC exhibits a 2.4-fold increase in current density with respect to that without laser processing, raising the cathode mass-specific power density to 8.79 kW g⁻¹ with 1 atm oxygen and 12.0 kW g⁻¹ with 1.5 atm oxygen.