Activity for the oxygen reduction reaction of the single crystal electrode of Ni modified with Pt

Activities for the oxygen reduction reaction (ORR) were investigated on Ni low index surfaces modified by electrochemical deposition of Pt (Pt/Ni(hkl)) and then thermal annealing. The ORR current density at 0.9 V (RHE) of the Pt/Ni(111) without annealing is three times higher than that of Pt(111). However, the Pt/Ni(111) without annealing has a low durability, with the activity reduction of more than 50% after 1000 potential cycles between 0.6 V and 1.0 V. The catalytic activity and durability are improved by annealing of Pt/Ni(111). The ORR activity of the Pt/Ni(111) with annealing at 650 K is 1.7 times higher than that without annealing and the decrease of the activity is less than 10% after 1000 potential cycles. The annealing process stabilizes the Pt-rich shell on Ni(111). (C) 2016 Elsevier B.V. All rights reserved.