Highly active and stable Pt electrocatalysts promoted by antimony-doped SnO2 supports for oxygen reduction reactions

• Sb doped SnO2 nanoparticles (ATO) synthesized with conductivity of 1.13 S cm−1.
• Pt nanocatalysts supported on ATO and ATO composite prepared.
• Higher specific activity and improved stability for Pt/ATO.
• Higher mass activity and improved stability for Pt/C-ATO.
• Active and durable catalysts due to the ATO phase and its modification of Pt electronic structure.

Alternative composite supports for platinum catalysts were synthesized from antimony doped tin dioxide (ATO) nanoparticles. In the range of the antimony content from 0 to 11 mol%, the highest electrical conductivity of 1.1 S cm−1 at 130 °C was obtained for the 5 mol% Sb ATO, from which composite supports composed of oxides and carbon and supported platinum catalysts were prepared. Using the pure oxide support, the Pt/ATO catalyst displayed superior specific activity and stability for the oxygen reduction reactions (ORRs). Low surface area of ATO caused poor dispersion of Pt particles compared to composite supports, which limited the mass activity of the supported catalysts. When the ATO composites were used as supports, the Pt/C-ATO catalysts showed significantly enhanced catalytic activity and durability for the ORR, attributable to the high ECSA and modified electronic structure of Pt by the ATO phase in the catalyst support.

Antimony doped tin dioxide (ATO) nanoparticles with high electrical conductivity were employed as the alternative support for Pt catalysts for oxygen reduction reactions. The synthesized catalysts displayed the superior activity and stability for ORR with ATO or its composite as support, attributed to the modified electronic structure of Pt by the ATO phase.Figure optionsDownload as PowerPoint slide