High-Performance Hybrid Catalyst with Selectively Functionalized Carbon by Temperature-Directed Switchable Polymer
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- 作者：Namgee Jung ; Sang Moon Kim ; Do Hyun Kang ; Dong Young Chung ; Yun Sik Kang ; Young-Hoon Chung ; Yong Whan Choi ; Changhyun Pang ; Kahp-Yang Suh ; Yung-Eun Sung
- 刊名：Chemistry of Materials
- 出版年：2013
- 出版时间：May 14, 2013
- 年：2013
- 卷：25
- 期：9
- 页码：1526-1532
- 全文大小：441K
- 年卷期：v.25,no.9(May 14, 2013)
- ISSN：1520-5002
文摘
Carbon-supported Pt (Pt/C) catalyst was selectively functionalized with thermally responsive poly(N-isopropylacrylamide) (PNIPAM) to improve water transport in the cathode of proton exchange membrane fuel cell (PEMFC). Amine-terminated PNIPAM selectively reacted with the functional group of 鈭扖OOH on carbon surfaces of Pt/C via the amide reaction by 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC) as a catalyst. Pt surfaces of Pt/C were intact throughout the carbon surface functionalization, and the carbon surface property could be thermally changed. The PNIPAM-functionalized Pt/C was well-dispersed, because of its hydrophilic surface property at room temperature during the catalyst ink preparation. In sharp contrast, when PEMFC was operated at 70 掳C, PNIPAM-coated carbon surface of Pt/C became hydrophobic, which resulted in a decrease in water flooding in the cathode electrode. Because of the switched wetting property of the carbon surface, PEMFC with PNIPAM-functionalized Pt/C catalyst in the cathode showed high performance in the high current density region. To explain the enhanced water transport, we proposed a simple index as the ratio of systematic pressure (driving force) and retention force. The synthetic method presented here will provide a new insight into various energy device applications using organic and inorganic composite materials and functional polymers.