Institute for Sustainable Energy/College of Sciences, Shanghai University, 99 Shangda Road, Shanghai, 200444, P. R. China.
Chem Asian J. 2022 Jul 1;17(13):e202200338. doi: 10.1002/asia.202200338. Epub 2022 May 4.
Developing a facile and eco-friendly method for the large-scale synthesis of highly active and stable catalysts toward oxygen reduction reaction (ORR) is very important for the practical application of proton exchange membrane fuel cells (PEMFCs). In this paper, a mild aqueous-solution route has been successfully developed for the gram-scale synthesis of three-dimensional porous Pt nanospheres (Pt-NSs) that are composed of network-structured nanodendrites and/or oval multipods. In comparison with the commercial Pt/C catalyst, X-ray photoelectron spectroscopy (XPS) demonstrates the dominant metallic-state of Pt and electrochemical impedance spectroscopy (EIS) indicates the substantial improvement of conductivity for the Pt-NSs/C catalyst. The surfactant-induced porous network nanostructure improves both the catalytic ORR activity and durability. The optimal Pt-NSs/C catalyst exhibits a half-wave potential of 0.898 V (vs. RHE), leading to the mass activity of 0.18 A mg and specific activity of 0.68 mA cm which are respectively 1.9 and 5.7 times greater than those of Pt/C. Moreover, the highly-active Pt-NSs/C catalyst shows a superior stability with the tenable morphology and the retained 78% of initial mass activity rather than the severe Pt aggregation and the only 58% retention of the commercial Pt/C catalyst after 10000 cycles.
开发简便且环保的方法来大规模合成对氧还原反应（ORR）具有高活性和稳定性的催化剂对于质子交换膜燃料电池（PEMFCs）的实际应用非常重要。在本文中，成功开发了一种温和的水相溶液路线，用于克级合成由网络结构纳米树枝状和/或椭圆形多足组成的三维多孔 Pt 纳米球（Pt-NSs）。与商业 Pt/C 催化剂相比，X 射线光电子能谱（XPS）表明 Pt 主要呈金属态，电化学阻抗谱（EIS）表明 Pt-NSs/C 催化剂的导电性有显著提高。表面活性剂诱导的多孔网络纳米结构提高了催化 ORR 的活性和耐久性。最佳的 Pt-NSs/C 催化剂的半波电位为 0.898 V（相对于 RHE），导致质量活性为 0.18 A mg-1 和比活性为 0.68 mA cm-2，分别是 Pt/C 的 1.9 倍和 5.7 倍。此外，高活性的 Pt-NSs/C 催化剂具有优越的稳定性，形貌保持稳定，初始质量活性保留 78%，而商业 Pt/C 催化剂在 10000 次循环后严重的 Pt 聚集，仅保留 58%。
