Design of active Pt on TiO2 based nanofibrous cathode for superior PEMFC performance and durability at high temperature
Design of active Pt on TiO2 based nanofibrous cathode for superior PEMFC performance and durability at high temperature
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DOI：
10.1016/j.apcatb.2016.11.053
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发表时间：
2017-05-05
影响因子：
22.1
通讯作者：
Shul, Yong-Gun
中科院分区：
文献类型：
--
作者：
Ji, Yunseong;Cho, Yong Il;Shul, Yong-Gun
阴极催化剂的氧还原反应（ORR）活性和稳定性是实际应用中的重要问题，高温聚合物电解质膜燃料电池（HT-PEMFC）材料更是需要考虑的问题。为了改善这些性能，改性催化剂的电子结构和寻找耐用的载体可能是一个很好的方法。本研究制备了一种由碳纳米管（CNT）缠绕的Pt/TiO 2纳米纤维复合电极（CNT-Pt/TiO 2）。我们的方法利用了CNF的电化学导电性以及TiO 2的耐腐蚀性和Pt纳米颗粒与TiO 2纳米纤维之间的强金属-载体相互作用（SMSI）的更好的稳定性，以减少Pt溶解。我们还发现，Pt的电子状态可以通过与相邻的CNT和TiO 2的相互作用而改变，导致Pt d-带空位的减少以增强催化活性。此外，具有独特的3D孔结构的纳米纤维组织结构提供了更高的表面积，用于进一步改善传质。这些结果表明，CNT-Pt/TiO 2纳米晶基电极与商业Pt/C（461 mW cm（-2））相比显示出增强的性能，最大功率密度为567 mW cm（-2），在120 ℃和RH 40%的苛刻条件下具有显著的耐久性。(C)2016爱思唯尔B. V.保留所有权利。
Oxygen reduction reaction (ORR) activity and stability of the cathode catalyst are important issues for practical applications, which should be even considered for the materials in high temperature polymer electrolyte membrane fuel cells (HT-PEMFCs). To improve these properties, modification of the catalyst electronic structure and finding durable supports can be a good approach. In this study, we synthesized a noble nanofibrous composite electrode which consist of carbon nanotube (CNT)-winded Pt/TiO2 nanofiber (CNT-Pt/TiO2). Our approach takes advantages of the electrOchemical conductiVity of CNF as well as better stability from the corrosion resistivity of TiO2 and strong metal-support interaction (SMSI) between the Pt nanoparticles and TiO2 nanofibers for less Pt dissolution. We also found that the Pt electronic state can be changed by an interaction with neighbouring CNT and TiO2, resulting a decrease of Pt d-band vacancy for enhanced catalytic activity. Furthermore, nanofibrotis structure with a unique 3D pore structure provides higher surface area for additional improvements of the mass transfer. These results reveal that the CNT-Pt/TiO2 nanofiber based electrode shows enhanced performance with the maximum power density of 567 mW cm(-2) compare to commercial Pt/C (461 mW cm(-2)) with a significant durability at harsh conditions of 120 degrees C and RH 40%. (C) 2016 Elsevier B.V. All rights reserved.