Pt3Ni(1 1 1) is the most efficient catalyst for the oxygen reduction reaction. Herein, we investigated the oxidation process of Pt3Ni(1 1 1) by time‐resolved X‐ray photoemission spectroscopy experiments with synchrotron radiation. For O2 exposure at room temperature, two well‐distinct O species are present with a sticking coefficient of 0.23–0.24 in the temperature range of interest for fuel‐cell technology. We show that the Pt skin of Pt3Ni(1 1 1) is selectively replaced by Ni2O3 and NiO surface‐skin layers upon heating in an O2 environment at 700 and 900 K, respectively. By dosing with O atoms, the formation of PtO is possible at 293 K, whereas Ni2O3 is formed at 353 K.
1 Feb 2016
Volume: 8 Issue: 4 Pages: 713-718