Bipyridine-based polybenzimidazole as a nitrogen-rich ionomer and a platinum nanoparticle support for enhanced fuel cell performance
Bipyridine-based polybenzimidazole as a nitrogen-rich ionomer and a platinum nanoparticle support for enhanced fuel cell performance
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DOI：
10.1016/j.fuel.2021.122954
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发表时间：
2022-03
期刊：
影响因子：
7.4
通讯作者：
M. Berber;Asma M. Alenad;N. A. Althubiti;Z. Alrowaili;Zaki N. Zahran;M. Yagi
中科院分区：
文献类型：
--
作者：
M. Berber;Asma M. Alenad;N. A. Althubiti;Z. Alrowaili;Zaki N. Zahran;M. Yagi
高密度氮载体，特别是金属催化剂的氮基聚合物载体是提高氧还原反应（ORR）催化活性并相应提高燃料电池（FC）性能的热门话题。在这里，我们提供了一种很有前景的富氮高导电聚合物膜电极组件（MEA）；即，聚(联吡啶-5,5'-联苯并咪唑)(BipyPBI)。 MEA 包含 BipyPBI 作为膜和铂 (Pt)/BipyPBI 功能化多壁碳纳米管作为电极。所制备的材料通过 NMR、XPS、TEM、XRD 和 TGA 进行表征，并通过 CV、LSV、电流电势和功率密度测量进行催化评估。通过电化学阻抗谱（EIS）诊断燃料电池的性能。 BipyPBI 的使用提供了高活性燃料电池电极，Pt 催化剂均匀分布在碳纳米管表面。值得注意的是，与传统的 PBI 电极相比，BipyPBI 电极的 ORR 起始过电位降低了约 10 mV，半波电位正移了 41 mV，扩散限制电流增加了 36 mA/mgPt。重要的是，基于 BipyPBI 的 MEA 的功率密度达到 0.893 W/cm2 (1.48 W/mgPt)，而 PBI-MEA 的功率密度为 0.549 W/cm2 (0.94 W/mgPt)。 EIS 结果表明，由于 BipyPBI 的高密度氮结构增强了质子传导和反应动力学，BipyPBI 基 MEA 的欧姆电阻和电荷转移电阻有所改善。这些成果丰富了燃料电池的研究，并激发了相关领域研究人员的兴趣。
High density nitrogen supporters, in particular nitrogen-based polymeric supporters of metal catalysts is a topic of high interest to boost the catalytic activity of oxygen reduction reaction (ORR), and accordingly improve fuel cell (FC) performance. Here, we offer a promising membrane electrode assembly (MEA) of a nitrogen-rich and highly conductive polymer; namely, poly(bipyridine-5,5′-bibenzimidazole) (BipyPBI). The MEA comprised BipyPBI as the membrane and platinum(Pt)/BipyPBI-functionalized multiwalled carbon nanotubes as the electrodes. The fabricated materials characterized by NMR, XPS, TEM, XRD, and TGA, and catalytically evaluated by CV, LSV, current-potential, and power density measurements. The fuel cell performance diagnosed by electrochemical impedance spectroscopy (EIS). The use of BipyPBI provided highly active fuel cell electrodes with a homogenous distribution of the Pt catalyst on the surface of carbon nanotubes. Notably, the onset overpotential of ORR lowered by ∼10 mV, the half-wave potential positively shifted by a 41 mV, and the diffusion-limiting current increased by 36 mA/mgPt, when the BipyPBI-based electrode compared to the conventional PBI-based electrode. Importantly, the power density of BipyPBI-based MEA reached 0.893 W/cm2(1.48 W/mgPt) compared to 0.549 W/cm2(0.94 W/mgPt) for the PBI-MEA. The EIS results indicated an improvement in the ohmic and charge transfer resistances of BipyPBI-based MEA, thanks to the high density nitrogen structure of BipyPBI which enhanced the proton conduction and the reaction kinetics. These results enrich the fuel cell research, and stimulate researchers engaged in related fields.