Structural Control of PtNi Catalysts through Precise Synthesis Conditions and Elucidation of Property Determinants by Operando XAS Analysis

• Published in: Electrochemistry
• Main Authors: Weijie CAO, Neha THAKUR, Mukesh KUMAR, Mitsuhiro MATSUMOTO, Ryota SATO, Toshiharu TERANISHI, Hideto IMAI, Yoshiharu UCHIMOTO
• Format: Article
• Language: English
• Published: The Electrochemical Society of Japan 2025-03-01
• Subjects: orr catalyst; operando xas; ptni nanowire; proton exchange membrane fuel cells
• Online Access: https://www.jstage.jst.go.jp/article/electrochemistry/93/3/93_25-00010/_html/-char/en
• ISSN: 2186-2451

PtNi alloy catalysts exhibit shape-dependent oxygen reduction reaction (ORR) activity and durability, influenced by synthesis conditions. In this study, a standardized synthesis method was developed by controlling the heating rate during nanowires (NWs) formation, yielding three distinct PtNi NW catalysts. Among these, PtNi-NW-3, featuring a rough surface with abundant high-index facets, demonstrated exceptional ORR activity and durability, achieving a mass activity of 1.06 A mgPt−1 and a specific activity of 2.73 mA cmPt−2, outperforming commercial Pt/C catalysts. The superior performance was attributed to reduced oxygen-binding energy and suppressed Pt oxidation, as revealed by operando high-energy-resolution fluorescence-detected X-ray absorption spectroscopy (HERFD-XAS). This work not only standardizes NW synthesis for improved reproducibility but also provides critical insights into the relationship between structural features and catalytic behaviours, paving the way for next-generation electrocatalysts.