Enhanced Oxygen Reduction Reactions and Stable Long-term Activity on TiO 2 -supported Dealloyed PtCu Nanoparticles in Acidic Aqueous Solutions

Dealloyed PtCu nanoparticles (NPs) were prepared on titanium oxide (TiO 2 ) surfaces with chemical reduction of Pt and Cu ion precursors using a reducing agent in an organic solvent containing TiO 2 , which was followed by an electrochemical dealloying process of potential cycling (-0.2~1.2 V vs. RHE). Dealloyed PtCu NPs/TiO 2 shows higher and substantial electrocatalytic activities towards oxygen reduction reactions (ORR) compared to conventional carbon black-supported Pt NPs (Pt NPs/CB). The current densities at 0.9 V ( vs. RHE) were -4.0 and -2.0 mAcm -2 on dealloyed PtCu NPs/TiO 2 and Pt NPs/CB, respectively.