Electrochemical Stability Studies of Nanostructured Carbon Based Pt-Cu Electrocatalysts for the Oxygen Reduction Reaction

• Published in: Meeting abstracts (Electrochemical Society) Vol. MA2018-02; no. 44; p. 1484
• Main Authors: Valenzuela-Muñiz, Ana Maria, Pech-Pech, Ildefonso Esteban, Verde Gómez, Ysmael
• Format: Journal Article
• Language: English
• Published: 23.07.2018
• ISSN: 2151-2043; 2151-2035
• DOI: 10.1149/MA2018-02/44/1484

One of the main objectives for the large-scale commercialization of proton exchange membrane fuel cells (PEMFC) is the reduction of the active metals loading at the electrodes, since the most utilized is the platinum (Pt) a very expensive material. As a feasible alternative, alloys and core-shell nanostructures are being studied in order to achieve this goal. However, the stability of these types of structures is still a drawback. On the other hand, carbonaceous materials are historically used as support of the metallic particles; the intrinsic characteristics of carbon have allowed creating better electrocatalysts. In this research work, an extensive study of the electrochemical stability of Pt-Cu/Carbon system was performed. Pt-Cu nanostructures were supported over different carbonaceous materials, and the performance towards the oxygen reduction reaction (ORR) in acid medium was evaluated. The nanoparticles were obtained by chemical reduction method using sodium borohydride as reducing agent and hexadecyltrimethylammonium bromide as surfactant at room temperature and without applying inert atmosphere. Cooper nanoparticles were enriched with Pt on their surfaces and supported on two different supports; Vulcan XC-72 Carbon and Carbon Nanotubes, keeping the metal loading below 10 wt.%. The Pt-Cu nanoparticles show spherical morphology and average size of around 10 nm as determined by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Structural characterization by X-ray diffraction (XRD) and electrochemical analysis obtained by linear and cyclic sweep voltammetry reveal that the structure of the Pt-Cu nanoparticles as well as their electrochemical stability to catalyze the ORR are dependent on both, the nature of the nanoparticle structure as well as the support. The obtained results could have a significant impact on the design of new nanostructured cathodic electrocatalysts for clean energy conversion in a PEMFC, and will be presented at the conference.