Core Dominated Surface Activity of Core鈥揝hell Nanocatalysts on Methanol Electrooxidation

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• 作者：Tsan-Yao Chen ; Tzy-Jiun Mark Luo ; Yaw-Wen Yang ; Yu-Chen Wei ; Kuan-Wen Wang ; Tsang-Lang Lin ; Ten-Chin Wen ; Chih Hao Lee
• 刊名：The Journal of Physical Chemistry C
• 出版年：2012
• 出版时间：August 16, 2012
• 年：2012
• 卷：116
• 期：32
• 页码：16969-16978
• 全文大小：586K
• 年卷期：v.116,no.32(August 16, 2012)
• ISSN：1932-7455

文摘

The activity of core鈥搒hell nanoparticles (NCs) in electrooxidation of methanol (MOR) was found to be dependent on the crystalline structure of the core and the lattice strain at the core鈥搒hell interface. Ru-core and Pt-shell NCs delivered 6.1-fold peak MOR current density at 鈭?35 mV than Pt NCs, while the Co-core and Pt-shell NCs showed a 1.4-fold peak MOR current density at 280 mV. The current density is improved by the compressive lattice strain of the surface that is caused by the lattice mismatch between the Pt shell and the Ru core. For Co-core NCs, the enhancement results from the ligand effect at surface Pt sites. In addition, the Ru-core NCs maintained a steady current density of 0.11 mA cm^鈥? at 500 mV in a half-cell system for 2 h, which is 100-fold higher than that of Pt NCs and Co-core NCs. These results provide mechanistic information for the development of fuel cell catalysts along with reduced Pt utilization and programmable electrochemical performance.