Increasing durability of Pt-surface-enriched nanosize structure catalysts by multi-step platinum deposition

• Published in: Journal of solid state electrochemistry Vol. 24; no. 10; pp. 2385 - 2393
• Main Authors: Kaplan, Dmitri, Goor, Meital, Burstein, Larisa, Popov, Inna, Shviro, Meital, Peled, Emanuel
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.10.2020; Springer Nature B.V
• Subjects: Accelerated tests; Analytical Chemistry; Bonding strength; Catalysts; Characterization and Evaluation of Materials; Chemical synthesis; Chemistry; Chemistry and Materials Science; Condensed Matter Physics; Durability; Electrochemical analysis; Electrochemistry; Electroless deposition; Electroless plating; Energy Storage; Enrichment; Iridium; Original Paper; Oxygen reduction reactions; Photoelectrons; Physical Chemistry; Platinum; Proton exchange membrane fuel cells; Scanning transmission electron microscopy; Spectrum analysis; X ray photoelectron spectroscopy; X-ray spectroscopy; Oxygen; Reduction; Synthesis; Platinum; Durability; Iridium; Catalyst
• ISSN: 1432-8488; 1433-0768
• DOI: 10.1007/s10008-020-04755-3

The sluggish reaction of oxygen reduction in proton-exchange membrane fuel cells (PEMFCs) and the durability of platinum-based catalysts have been major economical and technological barriers to the widespread application of PEMFCs. We report here on two Pt-surface-enriched nanosize structure (Pt-SENS) catalysts with iridium core, synthesized with the use of single-step and successive step-by-step electroless deposition of platinum. The synthesized catalysts were studied by energy-dispersive X-ray spectroscopy (SEM-EDS), X-ray photoelectron spectroscopy (XPS), and transmission scanning electron microscopy (STEM). Electrochemical analysis demonstrated improved oxygen reduction reaction (ORR) mass activity of the homemade catalysts by 25–30% compared with commercial 50%Pt/C catalyst and improved durability, by a factor of ~ 3, of the catalyst synthesized by successive step-by-step deposition following accelerated stress test (AST). Higher mass activities are attributed to better platinum utilization as a result of a Pt-surface-enriched structure, while greater durability is attributed to the stabilization of surface platinum by stronger Pt–Ir bonds induced by iridium atoms in the core.