Affiliation:
1. Department of Materials Science & Engineering National Yang Ming Chiao Tung University 1001 Ta Hsueh Road Hsinchu 30010 Taiwan
2. National Synchrotron Radiation Research Center 101 Hsin-Ann Road Hsinchu 30076 Taiwan
Abstract
AbstractThe stability and activity of Platinum catalysts under the redox process are the key parameters affecting catalytic performance. Here, we investigated the surface species evolution of low‐loading Pt catalyst deposited on a Nafion membrane through e‐beam deposition during redox reactions by using in situ X‐ray photoelectron spectroscopy (XPS) combined with a static electrochemical cell. Operando ambient‐pressure XPS measurement revealed the oxide species (Ptδ+, Pt2+, and Pt4+) evolution over different potentials in the water layer constructed by an acid solution. The amount of Pt2+ increased with an increment of the anodic potential, whereas Pt4+ suddenly formed when the threshold voltage of the oxygen evolution reaction was crossed. Hysteresis of Pt2+ was revealed as Pt4+ was completely reduced when returning to the open circuit potential. Incorporating depth‐profiling studies enabled us to uncover the mechanism of oxide species evolution between the surface and subsurface of the Pt catalyst during a redox reaction.
Funder
National Synchrotron Radiation Research Center
National Science and Technology Council
Subject
Inorganic Chemistry,Organic Chemistry,Physical and Theoretical Chemistry,Catalysis