Oxygen electroreduction on small (< 10 nm) and {100}-oriented Pt nanoparticles

Author(s)

Erikson, Heiki ; Antoniassi, Rodolfo M. ; Solla-Gullon, Jose ; Torresi, Roberto M. ; Tammeveski, Kaido ; Feliu, Juan M.

• Document type: Journal article
• Source: Electrochimica Acta; v. 403, p. 8-pg., 2022-01-20.

Abstract

Oxygen reduction reaction (ORR) was studied on {100}-oriented Pt nanoparticles with sizes from 3 to 7 nm in sulphuric acid solution. The distribution and size of nanoparticles was analysed by transmission electron microscopy and metal loading was determined by inductively coupled plasma optical emission spectroscopy. The synthesised nanoparticles have about 40% of Pt(100) facet and 10% Pt(111) as determined from Ge and Bi adsorption, respectively. The four Pt/C catalysts with metal loading from 25 to 38 wt% were tested for ORR activity in 0.5 M H2SO4 solution using the rotating disk electrode method. It was found that the ORR proceeds mainly via a 4-electron pathway with the rate-limiting step being the transfer of the first electron to O-2 molecule. The mass activities for ORR increase with decreasing the particle size, but specific activity has a maximum at 4.6 nm particle size. This means the most optimal {100}-oriented Pt size for ORR is around 4.6 nm in sulphuric acid solution. (c) 2021 Elsevier Ltd. All rights reserved. (AU)

• FAPESP's process: 17/15469-5 - Preparation of nanocatalysts with controlled morphology for applications in hydrogen purification and oxidation of contaminated hydrogen for electric energy generation
• Grantee: Rodolfo Molina Antoniassi
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 19/08051-0 - Reshaping of platinum nanoparticles from Pt/C by halide ions into electrochemical applications
• Grantee: Rodolfo Molina Antoniassi
• Support Opportunities: Scholarships abroad - Research Internship - Post-doctor
• FAPESP's process: 15/26308-7 - Optimization of the physicochemical properties of nano -structured materials for applications in molecular recognition, catalysis and energy conversion/storage
• Grantee: Roberto Manuel Torresi
• Support Opportunities: Research Projects - Thematic Grants