Pt nanorods supported on Nb-doped ceria: A promising anode catalyst for polymer electrolyte fuel cells

Abstract

For polymer electrolyte fuel cells (PEFCs), platinum nanoparticles supported on carbon black (Pt/C) serve as the commonly used hydrogen anode catalyst, exhibiting high activity for the hydrogen oxidation reaction (HOR), while the carbon support is susceptible to corrosion under PEFC operation. Here, a highly active HOR anode catalyst of Pt nanorod supported on niobium (Nb)-doped ceria without using corrosive carbon support was developed, which exhibits high durability at high potentials associated with hydrogen starvation. The production of hydrogen peroxide (H₂O₂), which can degrade the polymer electrolyte membrane, was also found to be significantly suppressed on the Pt nanorod/doped ceria catalyst. Density functional theory (DFT) calculations suggests that the Pt nanorod geometry and interaction with Nb and Ce favor HOR activity and stability while suppressing H₂O₂ production by modulating the adsorption of key reaction intermediates. This new catalyst has the potential to be used as an anode for high-performance and high-durability PEFCs.