A new article has been published in Applied Catalysis B by Mr. Park

게시일: Sep 20, 2012 2:27:57 PM

Hee-Young Park, Tea-Yeol Jeon, Jong Hyun Jang, Sung Jong Yoo, Kwang-Hyun Choi, Namgi Jung, Yung-Hoon Chung, Minje Ahn, Yong-Hun Cho, Kug-Sung Lee, and Yung-Eun Sung, “Enhancement of oxygen reduction reaction on PtAu nanoparticles via CO induced surface Pt enrichment”, Applied Catalysis B, 2013, 129(17), 375-381. (ELSEVIER, IF:5.625, Ranking: 6/135, ISSN: 0926-3373, published date:2013.1).

Abstract

To investigate the enhancement of the oxygen reduction reaction (ORR) activity on a carbon-supported PtAu alloy nanoparticle catalyst, the catalyst was subject to heat treatment at 423 K under a CO or Ar atmosphere. The surface composition was analyzed by XPS and the composition was shown to increase from 66 ± 2% (PtAu-AP) to 74 ± 2% (PtAu-CO) after heat treatment under a CO atmosphere, which was confirmed by electrochemical techniques, while the bulk composition was invariant at 55%. For the oxygen reduction reaction (ORR), the mass activity of PtAu-CO increased by 75.6% (33.2 A/g_Pt) when compared to that of PtAu-AP (18.9 A/g_Pt). Since the increase in EAS was only 15.8%, it was concluded that the specific activity was enhanced by 52.6% due to surface Pt segregation after heat treatment under a CO atmosphere. The enhanced specific activity was attributed to the reduced OH adsorption energy which was characterized by measuring the potential of total zero charge. The weaker OH adsorption was resulted from the higher Pt/Au ratio at the surface layers.

Graphical abstract

Figure options

Highlights

► Surface enrichment of Pt in PtAu nanoparticles was achieved by CO induced segregation. ► The Pt enrichment was characterized by XPS and electrochemical analysis. ► A higher Pt area and weaker OH adsorption enhanced oxygen reduction reaction.

Keywords

• Polymer electrolyte membrane fuel cell; Electrocatalysis; PtAu; Surface segregation; Pt enrichment;Oxygen reduction reaction