Negligible start-stop-cycle degradation in a PEFC utilizing platinum-decorated tin oxide electrocatalyst layers with carbon fiber filler

Niobium-doped SnO₂ is selected as an alternative carbon-free support material to negate carbon corrosion in polymer electrolyte fuel cells (PEFCs) electrocatalysts. The durability is measured using a membrane electrode assembly (MEA) over 60,000 start-stop cycles at high potential, equating to the lifetime of fuel cell vehicles. Using the Nb-doped SnO₂ support results in retention of 99% of the initial cell voltage. The current-voltage characteristics are improved by adding carbon nanofibers as fillers in the Nb-doped SnO₂, indicating that electronic conduction in the electrocatalyst layer is critical in the application ofmetal oxide-supported electrocatalysts.