Carbon-Supported High-Loading Sub-4 nm PtCo Alloy Electrocatalysts for Superior Oxygen Reduction Reaction

• Published in: Nanomaterials (Basel, Switzerland) Switzerland), 2023-08, Vol.13 (16), p.2367
• Main Authors: Xiang, Linlin, Hu, Yunqin, Zhao, Yanyan, Cao, Sufeng, Kuai, Long
• Format: Article
• Language: English
• Subjects: Alternative energy sources; Carbon; Carbon black; Carbon compounds; carbon support; Catalysts; Chemical reactions; Chemical reduction; Cobalt alloys; electrocatalysis; Electrocatalysts; Electrochemistry; Electrodes; Fuel cells; Fuel technology; high loading; Hydrogen; Identification and classification; Intermetallic compounds; Metals; Nanoalloys; Nanoparticles; Oxygen reduction reactions; Platinum alloys; Platinum base alloys; Properties; PtCo/C; Renewable resources; Temperature
• ISSN: 2079-4991; 2079-4991
• DOI: 10.3390/nano13162367

Increasing the loading density of nanoparticles on carbon support is essential for making Pt-alloy/C catalysts practical in H2-air fuel cells. The challenge lies in increasing the loading while suppressing the sintering of Pt-alloy nanoparticles. This work presents a 40% Pt-weighted sub-4 nm PtCo/C alloy catalyst via a simple incipient wetness impregnation method. By carefully optimizing the synthetic conditions such as Pt/Co ratios, calcination temperature, and time, the size of supported PtCo alloy nanoparticles is successfully controlled below 4 nm, and a high electrochemical surface area of 93.8 m2/g is achieved, which is 3.4 times that of commercial PtCo/C-TKK catalysts. Demonstrated by electrochemical oxygen reduction reactions, PtCo/C alloy catalysts present an enhanced mass activity of 0.465 A/mg at 0.9 V vs. RHE, which is 2.0 times that of the PtCo/C-TKK catalyst. Therefore, the developed PtCo/C alloy catalyst has the potential to be a highly practical catalyst for H2–air fuel cells.