Scientific reports 2013-01-01

Supported core@shell electrocatalysts for fuel cells: close encounter with reality.

Seung Jun Hwang, Sung Jong Yoo, Jungho Shin, Yong-Hun Cho, Jong Hyun Jang, Eunae Cho, Yung-Eun Sung, Suk Woo Nam, Tae-Hoon Lim, Seung-Cheol Lee, Soo-Kil Kim

Index: Sci. Rep. 3 , 1309, (2013)

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Abstract

Core@shell electrocatalysts for fuel cells have the advantages of a high utilization of Pt and the modification of its electronic structures toward enhancement of the activities. In this study, we suggest both a theoretical background for the design of highly active and stable core@shell/C and a novel facile synthetic strategy for their preparation. Using density functional theory calculations guided by the oxygen adsorption energy and vacancy formation energy, Pd₃Cu₁@Pt/C was selected as the most suitable candidate for the oxygen reduction reaction in terms of its activity and stability. These predictions were experimentally verified by the surfactant-free synthesis of Pd3Cu1/C cores and the selective Pt shell formation using a Hantzsch ester as a reducing agent. In a similar fashion, Pd@Pd₄Ir₆/C catalyst was also designed and synthesized for the hydrogen oxidation reaction. The developed catalysts exhibited high activity, high selectivity, and 4,000 h of long-term durability at the single-cell level.