Jung, Namgee Kim, Sang Moon Kang, Do Hyun Chung, Dong Young Kang, Yun Sik Chung, Young-Hoon Choi, Yong Whan Pang, Changhyun Suh, Kahp-Yang Sung, Yung-Eun 2024-01-20T12:30:35Z 2024-01-20T12:30:35Z 2021-09-05 2013-05-14 0897-4756 https://pubs.kist.re.kr/handle/201004/128056 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 -COOH 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 degrees 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. English AMER CHEMICAL SOC GAS-DIFFUSION LAYER OXYGEN REDUCTION CATHODE MICROSTRUCTURE OPTIMIZATION NANOTUBES MECHANISM OXIDATION IONOMER PEMFC High-Performance Hybrid Catalyst with Selectively Functionalized Carbon by Temperature-Directed Switchable Polymer Article 10.1021/cm303691e 1 CHEMISTRY OF MATERIALS, v.25, no.9, pp.1526 - 1532 CHEMISTRY OF MATERIALS 25 9 1526 1532 scie scopus 000319184600010 2-s2.0-84877748376 Chemistry, Physical Materials Science, Multidisciplinary Chemistry Materials Science Article GAS-DIFFUSION LAYER OXYGEN REDUCTION CATHODE MICROSTRUCTURE OPTIMIZATION NANOTUBES MECHANISM OXIDATION IONOMER PEMFC selective functionalization thermally switchable hydrophilicity water management flooding fuel cell