Effects of Hydrophobic Species on the Oxygen Reduction Reaction on the High-Index Planes of Pt3Fe

Abstract

Pt3Fe(111), Pt3Fe(775) = 7(111)–(111), and Pt3Fe(544) = 9(111)–(100) electrodes show the highest activity in the low-index planes, n(111)–(111), and n(111)–(100) series of Pt3Fe, respectively. The surfaces of these electrodes were modified with hydrophobic species such as THA+, melamine, and ionic liquid ([MTBD][beti]), and the effects on the oxygen reduction reaction (ORR) were studied. All the hydrophobic species improved the ORR activity on all the electrodes examined. The ORR activity of Pt3Fe(111) in 0.1 M HClO4 containing 0.1 μM melamine was 2.1 times higher than that of Pt3Fe(111) without melamine, giving 39 times higher activity than that of bare Pt(111). The durability was improved on all the electrodes examined in melamine-containing solution.