Improving the Ethanol Oxidation Activity of Pt-Mn Alloys through the Use of Additives during Deposition

Catalysts

Mohammadreza Zamanzad Ghavidel²  E. Bradley Easton¹ 

[1]Faculty of Science, University of Ontario Institute of Technology, 2000 Simcoe Street North, Oshawa, ON L1H 7K4, Canada

[2] E-Mail

关键词: Pt-Mn alloy;    additive;    heat treatment;    ethanol oxidation;    catalysts;    PEM fuel cell;    direct alcohol fuel cell;   

DOI  :  10.3390/catal5031016

来源: mdpi

【 摘 要 】

In this work, sodium citrate (SC) was used as an additive to control the particle size and dispersion of Pt-Mn alloy nanoparticles deposited on a carbon support. SC was chosen, since it was the only additive tested that did not prevent Mn from co-depositing with Pt. The influence of solution pH during deposition and post-deposition heat treatment on the physical and electrochemical properties of the Pt-Mn alloy was examined. It was determined that careful control over pH is required, since above a pH of four, metal deposition was suppressed. Below pH 4, the presence of sodium citrate reduced the particle size and improved the particle dispersion. This also resulted in larger electrochemically-active surface areas and greater activity towards the ethanol oxidation reaction (EOR). Heat treatment of catalysts prepared using the SC additive led to a significant enhancement in EOR activity, eclipsing the highest activity of our best Pt-Mn/C prepared in the absence of SC. XRD studies verified the formation of the Pt-Mn intermetallic phase upon heat treatment. Furthermore, transmission electron microscopy studies revealed that catalysts prepared using the SC additive were more resistant to particle size growth during heat treatment.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland.