Unifying ORR structure-activity-stability relationships of shape-controlled and highly defective PtNi/C electrocatalysts

R Chattot (1) , T Asset (1) , Olivier Le Bacq (2) , P. Bordet (3) , Jakub Drnec (4) , F. Maillard (1) , L. Dubau (1)

1 EIP - Electrochimie Interfaciale et Procédés
2 SIMaP - Science et Ingénierie des Matériaux et Procédés
3 NEEL - MRS - Matériaux, Rayonnements, Structure
4 ESRF - European Synchrotron Radiation Facility

Due to strain and ligand effects, the simultaneous presence of concave and convex surfaces and their highly-defective nanostructure (atomic vacancies, grain boundaries), highly defective hollow PtNi/C electrocatalysts have proven to enhance remarkably the oxygen reduction reaction (ORR) kinetics [1,2]. Likewise, PtNi aerogel [3], jagged PtNi nanowires [4,5] feature both high concentration of structural defects and enhanced ORR activity. On the other hand, and inspired from single crystal approach, nanostructured octahedral-shaped PtNi/C electrocatalysts exhibiting only Pt(111) facets are among the most active ORR electrocatalysts [6,7]. This presentation will show how structure-activity-stability relationships of this two classes of materials can be unified via a unique descriptor, the Surface Distorsion, derived from a physical parameter, the microstrain obtained from X-ray diffraction patterns [8].

Domaines: Catalyse

R Chattot, T Asset, Olivier Le Bacq, P. Bordet, Jakub Drnec, et al.. Unifying ORR structure-activity-stability relationships of shape-controlled and highly defective PtNi/C electrocatalysts. 70th Annual Meeting of the International Society of Electrochemistry, Aug 2019, Durban, South Africa. ⟨hal-02351778⟩