High specific surface area niobium-doped tin oxide nanoparticles produced in spray flames as catalyst supports in polymer electrolyte fuel cells

Platinum-loaded carbon is commonly used in polymer electrolyte fuel cells (PEFCs); however, it is known to corrode or degrade under high potentials, which results in poor cell performance. Niobium-doped tin oxide (Nb-SnO 2 ; NTO) nanoparticles are alternative materials to carbon because of their high durability and good cell performance as catalyst support in fuel cells. Here, we introduce the preparation of NTO nanoparticles with high specific surface area by spray flames. The particle characteristics and PEFC performances of the nanoparticles were evaluated. Spray combustion with a two-fluid nozzle was used where the raw material species were rapidly gasified to form fine nanoparticles. The spray flame synthesis was operated at a combustion enthalpy density of 4.87 kJ/g gas . This enabled homogeneous nanoparticle formation and suppressed particle growth under a minimal condition. The flame-made NTO nanoparticles showed a primary particle size and specific surface area of ~ 8.77 nm and 87.04 m 2 /g, respectively. Rietveld analysis revealed a detailed crystal structure of the NTO nanoparticles. In addition, Pt was loaded on the NTO nanoparticles and the cell performance of the resulting material was assessed using a membrane electrode assembly. The results of this study can be used to improve the features of flame-made NTO nanoparticles in order to suit the needs of a fuel cell application.