Electrocatalysis of oxygen reduction on CoNi-decorated-Pt nanoparticles: A theoretical and experimental study. (28th December 2016)

• Record Type: Journal Article
• Authors: Flores-Rojas, E.; Cruz-Martínez, H.; Tellez-Cruz, M.M.; Pérez-Robles, J.F.; Leyva-Ramírez, M.A.; Calaminici, P.; Solorza-Feria, O.
• Is Part Of: International journal of hydrogen energy. Volume 41:Number 48(2016)
• Page Start: 23301
• Page End: 23311
• Publication Date: 2016-12-28
• Subjects: ORR -- High energy milling -- Galvanic displacement -- Auxiliary density functional theory -- Adsorption energy -- Active sites; Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2016.10.009
• Languages: English
• ISSNs: 0360-3199

Abstract

Abstract: A CoNi-decorated-Pt (40:40:20 wt%) electrocatalyst was theoretically studied and experimentally validated for the oxygen reduction reaction (ORR) in acid media. To predict the activity of the electrocatalyst a Co16 Ni16 -decorated-Pt3 cluster was employed. The O and O2 adsorption energies were used as descriptors of the catalytic activity for the ORR. All calculations were performed using the density functional theory approach as implemented in the deMon2k code. A combined synthesis of high energy milling-galvanic displacement was performed to produce the CoNi-decorated-Pt electrocatalyst. The physical characterization of the electrocatalyst was developed using X-ray diffraction (XRD) for the phases identification, energy disperse X-ray spectroscopy (EDX) for compositional analysis and scanning transmission electron microscopy (STEM) to determine morphology and particle size of the synthesized electrocatalyst. Cyclic voltammetry and rotating disk electrode techniques were used for the electrochemical characterization of the synthesized electrocatalyst. The O and O2 adsorption energies showed that CoNi-decorated-Pt (Co16 Ni16 –Pt3 cluster) electrocatalyst represents an attractive candidate for the ORR. STEM micrographs showed homogeneous nanocrystalline particles of 5–10 nm size. The CoNi-decorated-Pt nanoparticles presented high specific activity, 40% above of the determined from Pt/C and similar mass activity from the same commercial Pt/C, used as comparison. Electrochemical results confirm the feasibility of a combined synthesis method to produce nanocatalysts which exhibit similar catalytic activity than that of commercially available Pt/C electrocatalyst. Highlights: A theoretical/experimental investigation was performed to propose a novel electrocatalyst for ORR. Adsorptions of O and O2 on Co16 Ni16 and Co16 Ni16 -decorated-Pt3 clusters were performed. A combined synthesis was performed to produce the NiCo-decorated-Pt/C electrocatalyst. High energy milling followed by galvanic displacement produced electrocatalysts with high specific activity.