Ionic Liquid-Modified Microporous ZnCoNC-Based Electrocatalysts for Polymer Electrolyte Fuel Cells
Ionic Liquid-Modified Microporous ZnCoNC-Based Electrocatalysts for Polymer Electrolyte Fuel Cells
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DOI：
10.1021/acsenergylett.9b01407
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发表时间：
2019-09-01
影响因子：
22
通讯作者：
Du, Shangfeng
中科院分区：
文献类型：
--
作者：
Wang, Min;Zhan, Huixin;Du, Shangfeng
非铂族金属(Non-PGM)氧还原反应(ORR)催化剂已被广泛报道，但由于其在酸性环境中的性能较差，其在质子交换膜燃料电池(PEMFCs)中的应用具有挑战性。本文采用[BMIM][NTf2]离子液体(IL)对微孔ZnCoNC催化剂进行改性，以研究其在质子交换膜燃料电池中的行为，并在实际操作中阐明其催化机理。ILS的高O-2溶解度提高了多孔锌CoNC的活性中心的利用率，其疏水性有利于燃料电池运行过程中的水传输。在高氯酸水溶液中的半电池测量表明，经20wt%IL修饰后，电子转移数从2.58增加到3.88，接近所需的4电子转移ORR。获得的功率密度在单电池PEMFC测试中提高了140%。该催化剂在碱性阴离子交换膜燃料电池中也产生了有趣的性能。
Non-platinum group metal (non-PGM) oxygen reduction reaction (ORR) catalysts have been widely reported, but their application in proton exchange membrane fuel cells (PEMFCs) is challenging because of their poor performance in acidic environments. Here, [BMIM] [NTf2] ionic liquid (IL) modification of microporous ZnCoNC catalysts (derived from ZIF-ZnCo) is investigated to study their behavior in PEMFCs and to elucidate the catalytic mechanisms in practical operation. The high O-2 solubility of ILs enhances the utilization of active sites with porous ZnCoNC, and their hydrophobic nature facilitates the water transport during fuel cell operation. The half-cell measurement in aqueous HClO4 shows that with the 20 wt % IL modification, the electron-transfer number increases from 2.58 to 3.88, approaching the desired 4-electron-transfer ORR. The power density obtained shows 140% improvement in single-cell PEMFC tests. The catalyst also yields an interesting performance in alkaline anion-exchange membrane fuel cells.